I gather Sheen’s big problem is that he managed to give himself a sex hernia. This happens with fair frequency in combination with cocaine or ecstasy.
In his situation, divorced three times, four kids, a heck of a lot of alimony, so his future earnings are limited. He has probably reached the conclusion that he will never be in a stable, happy marriage. So he probably sees hedonism as a serious option, especially with those who also don’t want to get married.
So he’s on the downhill side of life. With that lifestyle, he is not looking at an extended retirement, so, why not?
He needs to take up the piano with a very serious piano teacher who has (Catholic) Faith. I did that 8 years ago and there isn’t time for any bad habits. I’m 45 now.
Charlie Sheen will never have a stable relationship, but he might be a great pianist.