Hindsight's a bitch – it's easy to wonder how different things would be if Hitler got more hugs or someone said "No Jamie Lynn, not without a condom."

But someone who has no time for hindsight is Jack Nicholson. Though it's natural for people close to Heath Ledger to ask themselves if they could have done anything differently to stop his death, Jack Nicholson doesn't have to.

That's because Jack Nicholson says he warned Heath Ledger about taking sleeping pills. And if things are bad enough for Jack Nicholson to warn you about stuff…

Now that enough time has passed since Heath Ledger's death for those who didn't actually know him to get over the shock of the news, all that's left to do is wait to see what killed him and reflect on his work. Or if you're Jack Nicholson, both at once.

Although toxicology reports will clear the mystery up once and for all next week, pneumonia has already been ruled out and banknotes in his apartment apparently tested clean for illegal drugs, so the signs at the moment appear to suggest that Heath Ledger died from an accidental overdose of prescription drugs.

What's more, prescription drugs that Jack Nicholson of all people warned him to be careful with. Jack Nicholson has gone on record to tell the world that he'd previously spoken to Heath Ledger about his use of sleeping pills, as AOL reports:

"Heath's death is tragic news. I warned him about Ambien. I took it once and somebody called me in the middle of the night and I woke up in my car 50 yards from my house. I almost drove off a cliff. I didn't know where I was. Ambien can get you. Not through excessive use, it's just some people react more strongly than others."

Jack Nicholson spoke of these warnings to Heath Ledger at the London premiere of The Bucket List, which co-stars Morgan Freeman. That makes the film uniquely suited to Heath Ledger reflection because not only have Heath Ledger and Nicholson both played The Joker in movies, but Morgan Freeman also co-starred with Heath in the forthcoming The Dark Knight.

So if Jack Nicholson is telling stories about how he tried to get Heath Ledger out of his Drug Hell, what insights did Morgan Freeman have?

"I worked on The Dark Knight, but Heath and I never met, we were never on the same set, so this is as much news to me as it is to anybody and it affects me in the same way." 

OK, that one's probably a little less revelatory to be honest.

Anyway, the question is why Heath Ledger didn't heed Jack Nicholson's warning about the dangers of sleeping pills. We can't understand it – why would anyone not take the advice of a habitually-promiscuous 70-year-old potbellied man whose last major role mainly involved waggling a dildo around? It's a conundrum, that's for sure.

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Jack Nicholson Warned Heath Ledger - AOL