What tiny realisation hit you out of nowhere?

You know the kind: a thought that pops up while brushing your teeth or waiting for the kettle, and suddenly an ordinary thing looks completely different. Those belong here. A few flavours of shower thought:

Try to keep them original and phrased as a single idea, since the best ones fit in a sentence or two. Post yours as a title with a line of explanation if needed, build on other people's thoughts in the comments, and let the chat become a stream of consciousness.