I first started collecting objects during a three-year period of socialphobia, which began around the age of 13. I couldn't look anyone in the eye if they spoke to me (I still tend to look at mouths, not eyes) and crossed the road if there were people on the same side. Like a nervous cat, I became extremely anxious if I had to encounter anyone unfamiliar to me. I avoided going out unless it was essential, walking to school was a real trial (even facing the ground) and I decided to ignore all my friends and exist alone. I worried my parents.
First I collected matchboxes, then coins, stones and other natural objects. I stayed in my room and painted a picture every day until I had papered the entire room, including the ceiling, with paintings. I wrote bad poetry and learned to play the guitar. I did long headstands at lunchtime because it made me feel spaced out enough to go back to school. When I was washing I felt compelled to touch the different sides of my face the same number of times, counting carefully. I also had to place objects - like my shoes - symmetrically, or else I couldn't relax. I started to come out of it at 17, but didn't like what I found in society so at 20 I learned meditation and joined a religious (Hindu) cult, which is a whole other story.
Nowadays I can be pretty sociable, and just collect information; lots of it. As well as random items with no intrinsic meaning other than the fact that I've found them. They live in a drawer and aim to incorporate them in an 'oracle of random things'. Before that, I used to collect matchbox tops and old pennies - static and comforting when life hits a period of disorder. I can still feel anxious when I'm around people I don't know and teenagers scare me(!), but my sometimes obsessive perfectionism goes into other things, like mathematical patterns, an avid interest in computing, and validating and honing code in which these pages are hand-written until they are as compact and efficient as possible (which is incidentally kind to you and your browser).