You know how light always travels the fastest path, even though that’s obviously impossible and makes no fucking sense? Also, how the many-worlds interpretation is true? Bear with me, I’m going somewhere with this.
The you that experiences has to be alive, for obvious reasons. So any time there’s a world which diverges in a way such that you cease to be alive, that path isn’t taken from the perspective of the experiencing you. This feels like a continuous path through time, but what if it’s really a post-hoc picking of the worlds in which you survived? There seem to be real constraints on lifespans, but it’s possible that no one experiences dying until they’re out of possible worlds that keep them surviving. The yous that died of preventable stuff – car accidents, or whatever – aren’t around to clutter up your experience of liveness, since you can’t experience those branches. The word “you” is doing a lot of work in this paragraph, since I’m sort of divorcing it from the normal “you” concept. I apologize if this is confusing.
The obvious objection is that people do in fact die of, like, car accidents. But that’s not actually a problem! You didn’t die in a car accident. The fact that you can continue inhabiting a timeline where other people die is not a contradiction.
The other obvious objection is that this is crazy and makes no sense! That is a problem, I admit. But light traveling the fastest path is also crazy and makes no sense unless you assume that the “right” world gets chosen after the fact.*
Anyway. It’s probably not true. It’s also probably unfalsifiable. But I like it.
Even assuming this whole thing is true, it doesn’t license you to take extra risks. You can die perfectly easily in my experience, and I would rather you not.
* This is probably not true; wikipedia has some things to say about waves that I can’t really follow.
Clear, Simple, and Wrong 
The standard name for this is “quantum immortality”. It’s not a good thing, because the fact that there’s always a “you” that survives to be an observer, doesn’t mean you’re having a good time: in the worlds “nearby” the one where you died in a fatal car crash, most surviving observers still got hit by the car and are in horrible pain from their injuries.
For me, the moral is that measure matters: in a sufficiently large universe (not even necessarily quantum many worlds; a sufficiently spatially large universe contains a copy of you 101030 meters away), everything that can happen, happens somewhere, but it doesn’t happen equally often, and you really do care about the frequencies (you spend a lot more time having common experiences than uncommon ones).
Ah, I should have guessed it would have a name already. I find myself unswayed by the measure thing (and similar arguments) for no principled reason that I can articulate, though.