PhosphorusDecree I have the same effect. I can't sleep after socialising even if nothing big (for me) happens.
I can spend most of a day talking to my husband and that doesn't keep me awake so I guess it is new people and new ideas that are the issue.
I am guessing the answer is to socialise in a very controlled way - same group, same intervals, same length. I don't lie awake after social events that have become routine. This becomes more possible as you get older and there is less spontaneity, if not in you, in those of your age group. Less excitement, for sure, but I think making friends is a question of seeing the same, apparently boring, people often and building trust by virtue of not having creating any drama for them over a long period of time. It's natural for natural affection to build up. It is looking for "that special fantastic person" that has caused all my problems in life.
Other adults are potential playmates, not potential parents.
I guess I am saying, I hope you won't just assume this is carved in stone with you. Get curious about the wiggle room.
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Self-diagnosed with dyspraxia which has messed up my social life, my family, my work, and my home for a long time. I am ready for it to leave.
"From there to there, from here to there, funny things are everywhere!" Dr Suess, One Fish, Two Fish