Speaking as someone not diagnosed, coffee makes me completely hyper. I seldom drink it. One cup of bean to cup coffee makes me a nervous wreck, but I can handle a mug of instant. I have 3 cups of tea per day, the last one no later than 6pm, otherwise I'll be up all night. I think I'd possibly get an ADHD diagnosis tho' (ADD these days), which might be relevant.
My husband has AS traits, not diagnosed, but members of his family are quite obvious. He can have a coffee at bedtime and says it doesn't affect his sleep at all - but, his legs jump throughout the night. I think he's addicted. He gets defensive when I suggest he should cut down. But, he's definitely not affected like me.
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"We act as though comfort and luxury were the chief requirements of life, when all we need to make us really happy is something to be enthusiatic about." Charles Kingsley