Writing fan fiction is kinda just another way of playing with dolls, I think. I used to LOVE playing with dolls, it was my favourite activity as a kid, and I kept playing long after my friends considered it cool (I played till I was twelve, and I probably started lying and pretending I no longer played at around nine or ten or so). But it’s basically the same concept. You have characters with set personalities and traits, and then you play around with them, throwing them into different situations, pairing them up in different ways and creating whole new worlds for them to exist in. It’s pretty amazing.