Flying mittens

Conversation after the half-knit mitten went flying through the air, still attached to the ball of yarn:

T--Don't do that!

Me--(As I reel in the mitten from 10 feet across the room) Why not?

T--It just doesn't seem like a good idea. What's wrong with it anyway?

Me--It has dropped stitches.

T--How do stitches get dropped anyway? (For the record, she is a knitter, but not quite a Knitter)

Me--If I knew that, I wouldn't be throwing it across the room.