Miriam Margolyes: 'I'm 70 this year and still overweight, so I've learnt nothing'

Acting is controlled showing off and I was a born show-off I performed at school, at university in Cambridge, I was in Footlights, the Marlowe Dramatic Society, the Amateur Dramatic Club, and any drama group that would have me; I was driven.

I hate people massaging egos – saying things that aren't true, just to make others feel good. I like things to be sharp and unvarnished, though not cruel.

I've still not got it right One of the reasons I'm still performing is that I want to become a better actress than I am. And there are parts to play that I've not yet been offered; people still think of me as a lightweight – although not physically, of course – so recognition is important to me and I'm chuffed to buggery when I get it.

Being in 'Harry Potter' was just like every other job I'm not obsessed with it all, as some people seem to be. But it is thrilling to be part of something that has given a lot pleasure to people, and it makes me very happy when fans come up and want to get their picture taken with Professor Sprout; actually, I get furious if I'm not asked.

Most Americans are buttoned down when discussing sexual matters They don't want anybodyto have anything below waist. I always advise gay actors heading out there not to speak to the media about their sexuality because, unlike Ian McKellen, I don't think anyone's career should be sacrificed on the altar of gay rights.

My weight bothers me hugely It has overshadowed and crushed my life. I've let it happen through indiscipline, as food is one of my principal pleasures and I eat too much of it, particularly chopped liver. I'm going to be 70 this year and I'm still overweight, so I've learnt nothing; how ridiculous is that?

Education is the key to everything – including democracy: you can't have a thriving democracy without an educated demos, it just doesn't work. So I get quite melancholic about the cuts to our education budget; it's one of a number of bad mistakes being made in almost every area of policy that is indicative of the state of our country.

I deplore selfish swimmers What really makes me furious are pool Nazis. They're usually men, who pound up and down the lane, ignoring anyone nearby while they splash, hit and kick with impunity. Do I ever have a word? Oh yes! And If I could reach, I'd squeeze their testicles until their eyes watered.

I'm frightened of loneliness, illness, death, of not being liked and of not being good I may come across as carefree and forthright, but in the dark watches of the night, there is a terror underneath it all. The only thing I've become less nervous about is walking into a room full of people – talking is one of my favourite pastimes.

I'm drawn to my farmhouse in Tuscany It's a place where I find peace; I love the people, the food and the way that the light shines on the olive trees. It's the first house I bought and the best purchase I've made.

God is there for comfort, and I won't have it But I do think there is good and evil; we recognise them and know we have a choice, based on Judeo-Christian principles. It's funny, because I do belong to a synagogue in Streatham, and I very much like the Jewish club, though it doesn't like me, as I'm critical of Israel and its role in Gaza.

I don't often do musicals but appearing in Me and My Girl has been the happiest engagement I've ever had. It's a joyous show that touches on a theme still relevant 74 years after it was written: whether people can shake down together across social classes. adam jacques

Miriam Margolyes, 69, is an award-winning stage and screen actress. 'Me and My Girl' is at Crucible Theatre, Sheffield (sheffieldtheatres.co.uk) until Saturday