Years ago, I had a pretty low end job serving at pizza hut and we used to have an all you can eat pizza buffet. (I know, my stomach hurts thinking of it). We used to have this pasta casserole we'd serve. Basic stuff - Rotini, marinara, mozzarella.
Anyways, this one lady would come in every day, and she'd stay for the entire duration of the buffet. She would only take from the pasta casserole, load up her plate and go sit down. She'd then lift individual pasta noodles over her head, visible above her empty booth, and lick the the sauce off each noodle and place the clean noodle in another plate. She would proceed to do this to plateful after plateful of pasta, licking the sauce off. I think she would go through 8-10 full plates if pasta this way and the tray was constantly empty because of her noodle licking. Also....she used to wave her arms around like she was dancing... Eventually, and I mean a couple years later, she was banned from the restaurant because her behavior became increasingly erratic.
Edit We did offer her a bowl of warmed up marinara sauce on many occasions. She always refused.