We actively encourage teenagers not to have babies, we applaud young career women in their twenties, then before you know it you find yourself, as I did, aged 32 at a friend's wedding and being quizzed by everyone about why you haven't got round to reproducing yet.

Here's the truth. Your teens and twenties are your Plan A. At 50, you're assessing whether Plan B or Plan C or any of the other plans you hatched actually worked. Your sixties and seventies, they're an improvisation.

Movie acting is a great job for your twenties: You travel all over, you have affairs with people, and you throw yourself into one part and then another. It gets more challenging as you get older, and it's not just having a daughter, it's wanting to have your own life and be yourself.

Back in the day for me was a great time in my life - I was in my 20s. Most people refer to their experiences in their twenties as being a highlight in their life. It's a period of time where you often develop your own way, your own sound, your own identity, and that happened with me, when I was with a great teacher - Miles Davis.

'Sunset Boulevard' - the story of Hollywood movies draped on a depressing sex affair - is an uncompromising study of American decadence displaying a sad, worn, methodical beauty few films have had since the late twenties.

I feel like you don't know if someone's equipped for a romantic relationship until they're out of their twenties.

Positive, healthy, loving relationships in your twenties... I don't know if anyone would disagree with it: I think they're the exception, not the norm. People are either playing house really aggressively because they're scared of what an uncertain time it is, or they're avoiding commitment altogether.

When I was in my late twenties, a friend suggested that, since I was an avid SF reader and had been since I was barely a teenager, that since it didn't look like the poetry was going where I wanted, I might try writing a science fiction story. I did, and the first story I ever wrote was 'The Great American Economy.'

I'm torn about late parenting. I believe people should spend their twenties living and having fun and not having any regrets later. I also think people in their thirties generally make better parents but so many of my friends are having trouble - myself included - as fathers get older.

As far as hypnosis is concerned, I had a very serious problem when I was in my twenties. I encountered a man who later became the president of the American Society of Medical Hypnosis. He couldn't hypnotize me.

You see these casting directors' lists of characters, and they're all boxed in. Twenties is the hot girlfriend, thirties you can still be hot but moving swiftly to hot mum. Forties, you're the legal person in a pantsuit. Then, once you reach your fifties, you're positively elderly.

In your twenties, you think you are immortal. In your thirties, you hope you are immortal.

I didn't get into fitness until my late twenties. I had put on a lot of weight; I was quite chubby and feeling really depressed. But exercise helped everything - the body and the mind.

I don't think your twenties are for fitness, but when I got to my thirties I started to get fit.

At around 20 years old, I started to educate myself on nutrition. I'm so grateful that I taught myself the importance of health and fitness in my early twenties. I created a lifestyle that I love, and because of that, I've never had to diet.

I didn't read Western novels much until I was in my twenties, but I had a diet of them on film and TV, as well as other things, of course.

The prospect of dating someone in her twenties becomes less appealing as you get older. At some point in your life, your tolerance level goes down and you realize that, with someone much younger, there's nothing really to talk about.

I am haunted by what my life would have been had I not had the courage in my early twenties to leave Pittsburgh for New York City and really commit to being a writer. Pittsburgh is both post-industrial and provincial, and the opportunities there are limited. It would have been quite easy to simply drift through life.

Maybe I am a little bit guilty of trying to convince myself that I am cool to this point - even today. But I am so much more healthy than I used to be in my twenties, because I was not accepted at all.

I was a big party guy in my twenties, and kind of a playboy as well. I adopted a lot of values and goals that were fairly superficial and, in many cases, self-destructive. They looked cool and sounded sexy on the surface, but underneath, there was no real meaning going on, just a lot of escapism.

The Twenties have this sort of attitude where you never know what's around the corner.

Being a straight white guy in his, like, early twenties - there's some sort of thing about it. A sort of privilege, a sort of anger or something. You just say some really stupid things.

We're young. We're supposed to drink too much. We're supposed to have bad attitudes and shag each other's brains out. We were designed to party. We owe it to ourselves to party hard. We owe it to each other. This is it. This is our time. So a few of us will overdose, or go mental. Charles Darwin said you can't make an omelet without breaking a few eggs. That's what it's about - breakin' eggs - by eggs, I mean, getting twatted on a cocktail of class. As. If you could see yourselves... We had it all. We have fucked up bigger and better than any generation that came before us. We were so beautiful... We're screw-ups. I plan on staying a screw-up until my late twenties, or maybe even my early thirties. And I will shag my own mum before I let anyone else take that away from me!

My friend Madea has "attitude" that comes with wisdom. Back in our teens and twenties, we thought we knew everything and made all those foolish mistakes. Then, when we got a little older, at thirty, we started getting these flashes of light, revelations of what a great and lucky thing it is that we didn't get caught doing those stupid things back then. Around forty, if we are lucky, we stop lying to ourselves. Fifty and above, we've run out of patience for foolishness. Take me to the bottom line.