There are some, as someone said, of my interests that have been life long, and I know alot about. I can cite data and information and statistics on. Others come and go. My latest is Tarot. I don't believe in it as a ESP type thing, or for predicting the future thing.... I like it for bringing up ideas and concepts that you think about in relation to whatever you draw the cards for. There are symbols in each of the cards that make up the meaning. It's really cool.
I get so wound up about my interests that I dream about them and think about them and read about them, and talk about them, and they get in the way of everything.
I hyper focus so intensely everything starts relating to it as well. My brain connects everything to it. It can be painful at the beginning, and sad and depressing at the end. But I have always been that way.
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Meddle not in the affairs of dragons, for you are crunchy and taste good with ketchup.