Leonard: I'm done enabling him. Like, this is his spot and-and the thermostat has to be set to his comfort level, even though he doesn't even live here anymore and I'm always chilly.
Raj: Is that why you wear a hoodie all the time?
Leonard: Why would-- Yes! To accommodate Sheldon! And what-what about this-this thing? Why is it here? I'll tell you why. Because it was here when I moved in, and, for no earthly reason, he forbade me to touch it.
Amy: Well, if you don't like it, get rid of it. Put it in the closet.
Leonard: You know what, I will. [Leonard tries to move the helix structure. Lots of little beads fall off and come crashing to the floor]
Raj: I bet that's the reason.