The context of the following conversation is Sydney found seashells in the sand, and organized them into a bunch of straight lines.:
Sydney says I love finding these different seashells..
The friend responds I can see that!  You've found so many!  What did you do to them?.
Sydney responds I organized them by species, size, colour, density, weight, apparent age, and other factors, then lining them up alphabetically..
The friend responds Why are you going to all that trouble?.
Sydney responds I don't know.  But I feel such a powerful compulsion to do this, and since I started already, now I can't stop, no matter what..
The friend responds Dude, I think you might need to talk to a professional.  You might have OCD or something..