I'm an introvert.
I haven't always known this about myself, and for an introvert I have a pretty high social desire (that is, I like a lot more social time with people I know than your average introvert), but if you think about the introvert/extrovert dichotomy as a measure of how you gain and spend energy, I'm definitely an introvert. Introverts spend energy to be social and recharge when they're alone; extroverts get charged up by spending time with others and use it up if they're alone.
I've learned through years of observation and practice that I'm good for about 90 minutes of socializing in groups of more than four people, especially if those groups are more than a quarter new people (new to me, that is). Just me and a friend or two, I can go for hours, but I need to take a break after an hour and a half, two hours tops (and that last half hour I won't be at my best) in larger groups. I'm having fun the whole time, but I'll crash suddenly: exhaustion, crankiness, self-doubt. Time to go home, in other words. Best to time the homegoing to *before* I crash: it's hard to go home while I'm still having fun, but if I wait until the fun stops, that can color my memory of the entire time.
This morning I suddenly realized this is why family gatherings were so hard on me when I was a child: they went on for hours. Thanksgiving in my family started at 10:00 am. We'd all gather at the home of my nana or whichever aunt was holding it, or my home if Mom was in charge that year and spend the day together: chatting and playing cards or basketball, working on the food and setting the table, snacking through the day from the table of hors d'ouvres that would be refreshed or replaced with new dishes in waves during the day. Formal dinner at 3:30 or 4 pm in the fancy clothes we'd been wearing all day (hard to play in taffeta ruffles, white tights, and black patent Mary Janes), clean up, more chat, dessert around the fireplace. After a long evening extending the holiday, get home so late it was straight to bed for everybody.
It was torture.
All those hours of making conversation with my relatives exhausted me. Sitting alone in a corner reading? Not allowed: come help in the kitchen, talk to an uncle, or play a game with a cousin. Going for a walk alone to recharge? No way. It's no wonder I used to melt down completely, burst into tears and run from the room. Now I know how to take care of myself, but then I didn't know and it wouldn't have been permitted anyway.