Some people are just happiest being alone. I usually feel I am in this camp. I can have reasonably good social interactions but it's often awkward and even when it's not it is a lot of work and it doesn't seem commensurate with the reward, which is very little.

I like staying at home, reading, tinkering, doing my hobbies. I do not crave the company of others, and walking into a room and having to be "on" even with people I know and am friendly with is so draining.