Lifestyle choices have never been more important for a footballer. As competition has increased, so the margins for error have decreased.
When I started out, players could get away with not eating well. Even when I joined Manchester United in 1995, I didn't really take care of what I ate.
If I fancied some chips or pizza in the club canteen then I'd take it. The club employed a nutritionist who was popular but not always taken seriously. Anything he gave us was ridiculed as a magic potion.
Who you spend your social time with matters too. Most footballers grow up in working class backgrounds. I was raised in one of the poorest parts of Nottingham, not that it seemed so at the time.
Some of my best friends were wrong 'uns and still are. They have been in and out of prison. They are also still some of my best friends, but I don't get wrapped up in their world and they don't encourage me.
Some have seen the light and turned to jobs like social work to put something back into the community.
They protected me when I was younger. When they knew trouble was brewing, they'd send me home. I was only 15 or so, but they knew I had potential to be a footballer and didn't want me to waste it by getting in trouble with the police. I didn't want to be sent home by my mates, but I later realised that they were watching out for me.
Many footballers come from a similar background to me. Many have more talent than I had and still fail because they get involved with the wrong people or make the wrong choices themselves. There are plenty of failed footballers with tales to tell.
Maybe their mates didn't look out for them like mine did, because if you are going to be a top footballer then you can't be staying out all night. You have to make lots of sacrifices and even then it's tough.
I've seen many players make those sacrifices and then get to 21 or 22 having made it. They're sitting on a four-year contract and they look around and think: "I've got a lot of money, I'm a professional footballer, I've achieved my dream and I'm loving life."
It's natural that they want to let their hair down and enjoy themselves, natural that they want to meet girls. I'd be more worried if they didn't, but you need to make sensible decisions all the time, from how you spend the money to the company you keep.
You should never shun the mates with whom you have grown up and like you for yourself, in favour of hangers on who just want to be around a celebrity, but you must also realise that your life is different from theirs.
It's not easy when you move to a new city and everyone wants to be your best pal. You want to be friendly with people, but you don't know their motives. You need good people to advise you, not just a decent manager, but people your own age - maybe teammates who know the city well. They've probably had a similar upbringing to you.
I didn't go on a plane until football took me on one. I didn't take a foreign holiday with my partner until I was 22. We went to Florida and I was asked for my credit card at the hotel reception. I didn't own one and never had, nor had any of the people I grew up with. I had a bundle of notes, but they wanted a credit card. My agent had booked and paid for the holiday on his card.
Talent is only one part of being a footballer. You have to be mentally strong enough to take flak from all comers, from the media to your own fans.
You have to accept that people will read lies about you and there's little you can do about it. That you are being judged all the time, with snap verdicts aplenty.
Sign an autograph for a kid and him and his dad will think you are a legend for life. Don't sign it, even for a good reason, and you are an arrogant so and so.
You can live by those rules and understand that people are passionate and reactionary. You understand that fans are fickle and that they'll cheer you when you are scoring and boo you when you don't.
The only person you cannot kid is yourself. So you have to be true to yourself and make the right decisions.
Fabio Capello warned Andy Carroll, the Liverpool striker, this week over his lifestyle. "I think if he wants to be a good player, a good sportsman, he needs to drink less," Capello said of the striker, who has been in trouble with the police on several occasions.
Sometimes the hardest advice to take is the best: whether Carroll will listen to Capello remains to be seen.
Sometimes the best advice is the hardest to take, especially when it is dished out in public.
Andrew Cole's column is written with the assistance of European football correspondent Andy Mitten.