He's actually lucky to have made it to 42
All those drugs he took, he could have ODed many years prior.
Or suicided under the effects of drugs.
Or accidentally killed someone and ended up in jail, having shot a TV (once the bullets went into the next hotel room).
Or he could have been murdered by one of his Memphis Mafia for treating them like dirt and sleeping with their women (sometimes even their wife).
Or killed by Pricillia's father for breaking his vow not to sleep with her when she moved in at 16 (yes they were sleeping together).
42, in light of all of this, is a pretty long life.