While losing people like Jean Grey and Professor X is undoubtedly tough, that’s also not getting into all of the other people Wolverine would’ve encountered across his centuries of life. It’s no wonder he often resorts to alcohol to numb the pain, knowing he can’t get close to anyone because they’ll probably die long before he does. Suffice it to say, there are ways to defeat Wolverine, such as by drowning or encasing him in molten adamantium, the latter of which happens in the 2014 story arc “Death of Wolverine,” by Charles Soule and Steve McNiven. But without those few external sources, Wolverine could feasibly live for millennia, constantly bearing witness to the perpetual passage of time.
There’s one other aspect of Wolverine that protects from years of loss and death. Most people likely associate Logan’s memory loss to the experimentation he endured from the Weapon X program. That certainly plays a role to an extent, but in the comic book series “Wolverine: Origin,” from Bill Jemas, Joe Quesada, Paul Jenkins, Richard Isanove, and Andy Kubert, it’s further implied that Logan’s healing factor also impairs his memory to protect him from trauma. In essence, it “heals” his memories so that he doesn’t have to live with all of the terrible things he’s done and endured over the decades.
Even on the rare occasion when Wolverine does appear to bite the dust, it’s never too long before he’s resurrected in some manner. He’d probably be delighted to just stay dead, but the heroes of Earth (as well as Marvel’s profit margins) require him to return sooner or later.
