An inability to throw out or sell old toys and/or objects from your childhood as a result of seeing toy story (1, 2 or 3), and thus having an overly sentimental view upon these objects and imbuing them with anthropomorphic qualities. Ultimately a dangerous syndrome when combined with those partial to 'Hoarding'.
John: Wow Dave, you really do have a lot of junk lying around your house, didn't you have a garage sale recently?
Dave: Yeah, i did, but when i looked at those little G. I. Joes i used to play around with i remembered all the personalities i gave them, and all the games we used to play...
John: Yes, but now you are 34 years old and do not play with them anymore, and they sit gathering dust in an increasingly over packed room where something useful could be
Dave: I guess so, i suppose i might be coming down with Toy Story Syndrome