For me it is my late wife's 4 Chihuahua's. They were her fur-kid babies and they clung to her each and every day. I did promise to care for them, if/when she did pass, so here I am caring for them.

They are middle aged, around 7 to 10 years amongst the group of 4, so knowing how long Chihuahua's tend to stick around I've probably got another 5 to 8 years or so with them. After they pass and I add their ashes to my wife's, I am not sure why I would stick around...

Curiosity on how humanity works out over the next 40 years or so?

See if virtual reality technology develops to the point of total immersion (aka The Matrix), so I can escape to a new reality?

I don't have any agenda at this time, so unless something unforeseen happens, I guess this damn will to live thing will keep me around until the bitter end.