There's really no criteria for being my friend. I hardly have a lot of friends not because they didn't match my standard or anything but because I feel it'll save me a lot of trouble.

Humans are a hard nut to crack sometimes, if you're a teacher in a class of 100 students you'll notice that you'll end up going home every day with migraines,lol because they're a lot of personalities to work with and it's not easy.
I always like to keep my circle small because it'll less of a stress.

About the kind of people I relate with. I like smart people, smart and funny people, not the geeky kind who's always serious, we tend to relate more. I enjoy staying around real people, people who take life as it comes, people who're not negative, those who have a drive and work towards achieving their goal. There's really a lot of reasons but sometimes it's just easy to connect to some people the moment you just see them. It's like at first sight, haha.

I know I didn't answer your question really well but I just gave an insight