I am putting forward a bold conjecture that, all problems are ultimately existential. By problems, I mean those situations that need resolution in terms of understanding or explanation. My argument is that, all such resolutions have evolutionary effects. Good resolutions are advantageous and bad ones disadvantageous. (This last sentence is really just a definition.) A small problem might have a minuscule evolutionary effect, but the fact that it has even a tiny bit is enough for it to be considered existential when acting over the large time scales on which evolution is felt. A posteriori, one can also argue that, if the resolution of a problem had no evolutionary effect whatsoever, there would be no reason to spend our time and resources on it. In other words, those who do spend their resources on such problems are at a disadvantage and must have been (or will be) deselected by evolution against others who don't.