Many struggle with the fact they are under constant pressure to perform on a global stage. They live with high stress, and often with extreme emotional highs and lows.
Many players just want to fit in with their friends - be able to do what they do. Alcohol and drugs are ways to fit in, and they are ways to escape.
On the other side of this world are untold riches. Big-money contracts, endorsements and for some, brand currency for life, where they can leverage their sporting career long after retirement.
A teenage Tiger Woods once said to mentor Mark O'Meara that he just wanted to be free to live his life like a normal teenager. O'Meara said to him that if he gave back the private jet and billion dollars of endorsements, then absolutely, his whining would be justified.
And that's the reality for professional athletes - they have to find a way to live in their two distinct worlds. They have to make sure they don't collide, because in their high-performance world, late nights, drugs and booze are all detrimental to their performance.
Most of them are contractually prohibited from taking various substances and if any of them have sponsors, they can kiss them goodbye if they get caught on the wrong side of the law.
It's not foolproof, clearly, but top rugby players in this country are mostly adept at managing to stay out of trouble. They are almost angelic in comparison with players from other codes in other countries, but that doesn't mean that temptations and pressures aren't as strong here, as they are everywhere else.
Perhaps the perception isn't right, but it seems like booze and drugs scandals are relatively commonplace in the NRL, the NFL and the English Premiership. There now appears to be an underground drugs culture building in the French Top 14, something coming to light after former All Black Ali Williams and former Wallaby James O'Connor were arrested over the weekend respectfully for buying and possessing cocaine.
Williams' arrest came two weeks after Paris team-mate Dan Carter was charged with drink-driving. While Williams has earned the moniker 'Comical' Ali', his reputation in New Zealand was of a player prone to occasionally being a buffoon for what he said, rather than any illegal behaviour.
Carter, on the other hand, enjoyed a 15-year career in New Zealand as one of the game's purest players and athletes. Brand Carter is built on boy-next-door charm.
He's all about hard work, discipline, modesty and squeaky-clean living - a family man to the core. The farm boy who never forgot his roots, despite dabbling heavily in a different world of fashion brands and glamour.
He has said there were times when he hated the constant scrutiny he was under in New Zealand, but could that same pressure have been a factor in preventing him from ever tarnishing his reputation while he was an All Black?
He made a mistake a couple of weeks ago, getting into his car after a few glasses of wine in Paris. It was a mistake that would have been harder to make in New Zealand, where higher up in his thought process would have been the knowledge that he was known to everyone and his every move being watched.
It's hardly as if he's heading wildly off the rails, but with a little more freedom to be himself, he let his guard down too far.
This is more so the case for Williams. In New Zealand, he was "Ali Williams, All Black" and at an unmissable 2.02m tall, he couldn't exactly sneak around. In Paris, he's just some tall bloke and that anonymity must be liberating.
That same need to be permanently conscious about people watching and judging is probably no longer there, and he took the risk of buying cocaine.
