I had a funny experience with my book bag as a teen: it was one of those bags with two latches, but I always kept it closed with only one latch to make it easy to open at the door.
I get to this one door and the middle-aged lady opens the door with her small dog in her arms. The dog sees me and begins an incessant, and high-pitched barking (as some excitable small dogs are wont to do). Since the lady was holding this dog in her arms, these barks were emanating just inches from my ear. Needless to say, I found it a bit distracting to talk over the din.
As I was talking, my one latch gave way (must not have been fully tightened), and the case opened up as I was holding it by my side. The results were comical, as everything in my case exploded all over the front step. For a moment I just stood there, mortified, while the dog kept yapping at me. Finally, not knowing what to do, I began to pick up my belongings while I said the only thing I could think to say: "If you think that's something, wait till you see Act Two!"
Ah, bookbags...