Tim Minchin: 'Once I'd discarded the sheet music I would just be playing piano all the time'

We asked the musician, comedian and writer, 41, what his younger self would make of him today... 

A huge amount of my childhood was spent learning to put elastic bands around the testicles of young sheep. Growing up in Perth, Australia, we went camping all the time and spent a lot of weekends at family friends' farms.

My big brother was the main force in my life when I was very young. We thought we wanted to be farmers, which was crazy because when I went to my grandfather's farm I always ended up having an allergic reaction to the hay.

As a young child, I had ear infections, asthma and was allergic to various things. I spent a bit of time in hospital and was sort of pudgy. Mum thought I was probably a little slow.

Because of that I've always identified as starting slowly and from behind. It really wasn't until I was in my early teens that everything started sorting itself out. Although I was always good at jigsaws, and poems, which I guess with hindsight makes sense.

We were a close family. We did a lot of standing around the pianola singing in an almost nauseating Von Trapp fashion. We're still close. Even though my three siblings and I live far apart, we message each other every day.

I took up piano when I was eight because my brother was playing guitar. I did it for three years and then quit, but my brother kept bugging me to stick with it, not in an encouraging "you can do it" way, but more "sit down and play this intro I've worked out on the guitar". Once I'd discarded the sheet music, that's when it became this - if you ask my mum - annoying hobby. I would just be playing piano all the time, instead of studying.

Still, the young me would find what I've gone on to do a huge shock. Even now, when I'm playing the piano, I watch my hands and think, "How the hell did this happen?" I feel hugely grateful for it. My stage persona and look is just like how we played dress-up as kids. As soon as I stumbled into comedy, I thought, "OK, I'll do a Mozarty, Robert Smithy, Noel Fieldingy thing". It didn't feel significant - and it still doesn't.

At the age of 19, I auditioned for a contemporary music course at college. Up until then I thought there was no way I was good enough, which is strange as I'd written three scores for shows. But it took me years to accept that I was allowed to be an artist.

When I was in Melbourne playing in covers bands in my late 20s, although I'd written a lot of amateur music for theatre, I had a strong sense of my limitations. That I would ever get near the Royal Shakespeare Company, who asked me to do Matilda in 2009, would have been a shock. My whole career feels unbelievable. I was raised by modest parents who never told me I was special - which is an approach I intend to take with my children.

I always knew I wanted kids; I ended up marrying Sarah, my first girlfriend, so I never worried I might not go down the family route. I was always the teenager looking after the little children at family gatherings, and I don't think I'd be surprised that I've now written a children's book.

What has happened in my life, though, has so far exceeded what I could have set for myself in terms of opportunities and living around the world. At 19, Sarah and I went to England, backpacking, and found it cold and a bit disconcerting. To think that I've lived in London and LA and worked in New York, it's unbelievable. That said, I've had a pretty terrible year. I'm really struggling to deal with the loss of the movie I was working on, and my Groundhog Day musical closing in New York, despite seven Tony nominations. But I think my younger self would tell me to pull my head out of my a---. If you'd said to me 15 years ago, "Here's the career you'll end up having or here's a hundred million dollars," I'd have taken the career.

When I Grow Up by Tim Minchin, ill. Steve Antony (Scholastic, rrp £12.99) is available for £10.99 plus p&p: call 0844 871 1514 or visit books.telegraph.co.uk