my professional guess on the matter:
pie crust didn't forget a dog. he's just pretending he did to get massive, MASSIVE amounts of attention.
Why do people feel the need to richard with other people who they'll eventually forget about, anyways?
Sure, you could make the whole "living in the moment" argument, but I'll retort that all you're accomplishing by doing this is wasting you, our, and the entire multiverse of other possible good things you could be doing's time by being an starfish to strangers across the internet instead of doing something productive.
The few minutes it takes me to write my opinion and the countless hours it clearly takes Pie Crust to be either an obvious troll or disrespectful douchebag (pick two) could all be spent doing literally anything else more productive, and noone would be losers in the situation.
I seriously cannot put myself in the mindset of people like him, because all it seems to accomplish on his end is temporary satisfaction that will die in moments and leave the entire party slinging stuff at eachother until a permanent solution shows itself.
I wish people could all get along, but such thoughts wouldn't even come true in a perfect world. Such is life, I suppose.