Strength of character the 15th club in Jason Day's bag

With five wins, a first major triumph, the birth of his second child and a bout of vertigo, you'd think Jason Day would reflect on 2015 with adjectives like "awesome" or "eventful". But as the golfing superstar recalled what was arguably the standout Australian sporting season of 2015, it's education, rather than adulation, that comes to mind.

"Learning: that word would be learning," Day told ESPN. "It was more of a learning year for me.

"Obviously going into that year I never really expected to have the second half of the season pan out the way it did and I think I really learnt to believe and trust in my abilities and know that I am one of the best players in the world.

"And to be able to finally get over that hurdle of becoming a major championship winner and then also No.1 in the world for a brief period there gave me a lot of confidence but belief [too]. It was just, I learnt to get back into that habit of wanting to really buckle down and try to challenge the top guys for their spots and try and win as much as possible."

Day's finish to the year, which saw him claim four victories in the space of two months, followed a bout of vertigo that saw him collapse on course mid-round at the US Open. For many players, it would have been an easy excuse to opt out of golf in search of a full recovery. Day just went and claimed the world No.1 ranking instead.

"Yeah it's just something that you kind of ... vertigo, it's a hard thing to kind of explain," he said. "It's like you're spinning in a chair and then you try and get up and you try and walk and it's really difficult because you're just so dizzy.

"Any sport would be hard to play, even just living would be hard to function while you're dizzy. I mean golf is one of those sports where you need to see the ball, it's very static and you're trying to swing, and you use pretty much all your body parts to get the ball from A to B.

"So it can be very difficult to play competitive golf but, off course, if it didn't happen in tournament week I'd be sitting there in bed for two days straight just laying down and trying not to move because it's really difficult to function."

"I really thought my first major was going to be the Open Championship and unfortunately I left a putt short."

Jason Day

Just four weeks later Day fronted at St Andrews for the Open Championship. Three strong rounds put him right in contention going into the final day, only for a missed putt at the 72nd hole to revive memories of his late Masters collapse of 2013.

Again, it could have ushered in an abrupt end to Day's season. But just seven days later he dropped a 21-foot bomb to claim victory at the RBC Canadian Open - the putt thundering into the back of the cup to wipe away memories of his gentle roll in Scotland. The rest of the season sorted itself.

"Yeah, you know what, it all kind of happened, and I explained this last year, it all kind of happened to me at the end of the British Open where I played really good golf," Day told ESPN.

"I only made three bogies, they were all in the second round, but when I went over there I just felt really calm with myself, found this inner peace, and it kind of just felt like it was my time - like it was meant to be.

"I really thought my first major was going to be the Open Championship and unfortunately I left a putt short [to get into the play-off eventually won by Zach Johnson].

"But the next week usually it's very tough to come back after a week like that and try and compete and play well. And to be able to come back and win at Canada, and kind of nail that putt on the last hole and really show that I can do it, gave me a lot of confidence going forward.

"I was driving the ball great, I was hitting a lot of greens with my irons and putting fantastic; I mean just every putt went in and it was kind of like a dream run that you always think about when you're growing up as a kid.

"It was quite an impressive run for myself. This year's different but I'm going to give it a 100 percent every day and see how it goes."

If his amazing finish to the season wasn't enough, Day and wife Ellie then welcomed their second child, Lucy, in November. There hasn't been as much "learning" as their first attempt at parenthood but there has been somewhat of an education for first-time brother Dash.

"You know what, my first time around with Dash it was very difficult for me and Ellie just to kind of get a grip on what parenting is like and also trying to play competitive golf," Day said.

"Dash was a little bit of a terror for not going to sleep for two-and-a-half years and he sleeps like a log now which is great. Lucy is a complete angel - the total opposite to what Dash was. She sleeps well, she eats well and barely cries, so it feels like we've just added another person.

"But it really doesn't feel like I'm going from one to two kids because I've heard that it's very difficult going from one to two kids ... so it's neat to have them on the road with me; Dash, he wasn't too happy with us for the first three weeks but now he absolutely loves her."

A healthy family, fame and fortune; what else does one need? Certainly not a courtside collision between wife Ellie and NBA superstar LeBron James, as happened in December.

The recognition from another Australian sporting icon, the national rugby team, the Wallabies, was a nice surprise, though.

"Yeah I did follow their [the Wallabies'[ journey through the World Cup and the boys played very, very hard," Day said with a chuckle when asked about the gold strip sent his way by Kurtley Beale.

"I tell you what, the [New Zealand] All Blacks, [that was] probably the best team they've had, ever. It's just amazing just how great they played through the whole series.

"But it was really generous of the guys to send me a signed jersey -- it's going up in my office. Also, Kurtley Beale gave me a jersey so I wore that when they were playing and it's really neat to see that I've got support from them.

"And you know I was just trying to send them as much support as I could when I sent them a message before, I think it was the Scotland game. So it was fun to see the Wallabies sort of get back on top of things and hopefully they can keep the run going."

That will be a difficult assignment for the Wallabies, but an even tougher one for Day.

So far this season, he has recorded just the one top 10 - at the Hyundai Tournament of Champions in Hawaii - in three starts while at the weekend's WGC Cadillac Championship in Florida he finished in a tie for 23rd.

And the Queenslander finds himself contesting the most competitive period of golf since Tiger Woods' fall from grace, with fellow young guns Jordan Spieth and Rory McIlroy creating a "big three" at the top of the rankings -- not to mention the resurgence of fellow Aussie Adam Scott who claimed back-to-back PGA titles with a one-shot win at Doral.

Another five-win season and a second major title are tough acts to follow, and Day knows it.

The approach then?

"If I give it 100 percent, I can look at myself at the end of the year in the mirror and say I've given it 100 percent that's what I'm going to be most happy with."

Jason Day

"[I have] very similar goals to last year, which is no goals," Day said.

"The only goal that I have is that every day I come to work I give it a 100 percent. I explained this to Bud [Martin], my agent, the other day. I said: 'You know what, five wins was great last year. I'm going to give it a 100 percent every day this year; I'm very motivated to try and become more of a dominant player out there and try and get back to No.1 in the world and stuff like that'.

"But I was explaining to Bud that if I give it 100 percent, I can look at myself at the end of the year in the mirror and say I've given it a 100 percent that's what I'm going to be most happy with."

Long may the education continue.