If you aren't remembering, you must have had a bad knock.

[Chopper is more concerned about that right now. If it might be more serious, if the fall and knock on the head had impacted Usopp's memory somehow. He's not so worried about this bicycle or money, they could figure that out later. The more immediately concerning issue is Usopp.]

It's not your fault. If you hit your head and that has somehow impacted your memory. That could be really serious! You need to be careful!