To others, it might be a question with a too obvious answer but, there was one (recent) time that I was so lonely, and I tried to do a problem-solving approach, and yeah, my solution was--to figure out the things that can usually make me happy/smile. In a way, this can be a thread that will remind you how to rofl like mad or anything.
Pardon me, I always begin with spoilers:
Bookmarks