Isla Fisher: this much I know
The actor, 37, on Home and Away, Twitter and medicine

I know how to tap into my inner idiot. It’s a skill I learned at school. We moved a lot because of my dad’s job [he worked for the World Bank], so I started a new school every year, and in order to break the ice and make friends I had to do stupid things to make people laugh.

Growing up with four brothers was like being in the eye of a hurricane. We moved to Australia from Oman when I was six, and I had a great outdoorsy upbringing in Perth. I was a tomboy and enjoyed being the only girl. I’m at ease around men as an adult – I’m sure it’s because I grew up with so many boys.

Home and Away taught me how to look good in a bikini. And how to deliver bad dialogue convincingly – a skill that really helped in the early days of my career. For a long time I was auditioning for films that weren’t very good, but I’d get called back because I could make a terrible line sound real. For that I’ll always be grateful.

I value my privacy more than anything. Living so publicly via something like Twitter is overwhelming to me. I don’t talk about motherhood or my marriage – ever [she is married to Sacha Baron Cohen]. My children are my favourite topic privately, but I believe my daughters deserve to have a normal upbringing.

It’s humbling to start at zero every so often. I moved to Paris after Home and Away to go to clown school whilst my friends headed to LA to try and “make it”. I didn’t speak French and I felt so out of my depth. I was terrified for most of the year I was there, but eventually I broke through – my French became fluent and I enjoyed performing in a way that I hadn’t in a long time.

I blame my temper on the fact that I’m a redhead.

I’m a frustrated doctor. I have a massive medical encyclopaedia at home and I like to diagnose friends and family. I would never have been able to study medicine because my maths is so awful, but the book is my go-to the second someone has a sniffle. I never search for symptoms on Google, though – that ends in paranoia.

What you say no to is as important as what you say yes to. It’s a fine balance. If you’re not out there working and people aren’t seeing your face, then you’ll be overlooked. At the same time, you don’t want to say yes to everything, because people just get sick of you.

I love a handlebar moustache on a man.

I’m aware of my own limitations. I’d like to be a great writer, but I just have to read the Great Gatsby and I realise there’s no point in putting pen to paper. Equally I’d love to be a great yogi, but I know that I’ll never be a human pretzel. I’ll always be the sweaty one in the corner struggling to do a downward dog, and I’m OK with that.

Now You See Me is in cinemas on 3 July