Going to look at the Facebook page next.
Real life examples from my now 11 year old DS2 with ASD, include a long list of obsessions, which usually happen one at a time and last from several weeks to several months.
When he was 3 he had to run around the car 3 times before getting in which was fine when parked in the drive...
At 4 he knew the birthday of every child in his MS class, but couldn't recognise their faces.
At 6 he knew all the doctors (Who) and their companions for every story since 1963. God bless BBC website for that.
He knew the length of every David Bowie track
on every album when he was 8. Has forgotten them all now.
Hannah and the Pirate Caves game on Neopets lasted 2 years and included him joining a website for other addicts! How he found it I've no idea.
Now he just plays Final Fantasy 1 (not 2 of course!?) on his Ipod touch which I have long regretted buying. He prefers it to PC, the Wii or the TV. Has lasted 4 months so far.
As I've seen written before, just nod and smile and say "Oh, really! That's great."
He had a high pain threshold, which sounds like we were torturing him. He has sensory issues, loves loud noises, firm cuddles, but cannot eat food unless it is nearly cold. He's either laughing and happy, passive and unresponsive or completely devastated and can go from one state to the next in about 5 seconds. Life has not been dull since we had him!