All of us are more or less sewer rats, fantasizing about being in another (higher) dimension, like in the movie series 'Matrix'. In between you find time to have a few nookies here and there, sniff a few pleasant (to us) things, squeeze out a few litters, then you're dead.
Once you're dead, you're gone....Le fin.....
You didn't tag me but here goes.
About us being the only organisms is doubtful since existence of habitable planets (and existence of intelligent life) in Alpha Centauri and other distant solar systems within less than five light years is more or less possible.
I don't find it depressing because as organisms we are rather primitive, on a lower evolution stage and limited to only the five senses and some claim, maybe an intuitive sixth sense. Just because we cannot sense it, does not mean it does not exist. Things could exist beyond our perception level (vision, sight sound, touch etc.)
So resigning oneself into 'not doing anything' may not be the best option. As organisms, our seed (spermatozoa) behaves in pretty aggressive manner anyway, so 'not doing something' (especially if you are a male) is not in our biological signature or DNA. Watch sperm cell activity on YouTube sometimes....
