It seems obvious to me that only a few people are here for the Life's Great Adventure and most are killing time until they kick the bucket.

It seems obvious to you. You might want to scrutinize your intuitions more closely, because unless you believe in some telos to history then this doesn't make sense. It also prompts me to wonder whether you might possess some of the cluster of traits attributable to diagnosed sociopaths (as that word is often very loaded, let me note that sociopathy seems to just be a normal part of human variation comprising about 3 percent of the population, most of them neither particularly-accomplished nor particularly dangerous to others); there are other factors I can think of that might tweak your intuitions thus, but it certainly enters the picture there.

Who do you think counts as someone here for "Life's Great Adventure?" How do you distinguish these people, and on what basis do you conclude that this explains the traits they display rather than something else (statistical normalization acting on population genetics, circumstantial factors, spandrels of history, meddling deities, them being the ones the Simulation is about, or almost anything else...)