Oh gosh, I thought that too. I also thought the piggy bank was just a decorative object for some reason.I thought the bucket is only a odd helmet
2D Minecraft.
Oh, one other thing: I thought that natural background walls blocked enemy spawns and were valid for housing. I couldn't figure out why my NPCs wouldn't move in, and then the blood moon hit and my supposedly secure base was swamped. I figured out that the weren't valid for housing before EoC, but it probably wasn't until after Skeletron that I realized they permitted enemy spawns.