Untrustworthy Atoms

Listen up, buttercup. This joke is all about wordplay. See, atoms are tiny things that make up everything around us. But the phrase "make up stuff" also means to invent or fabricate things. So, the joke is that atoms can't be trusted because they literally make up everything, but also because they figuratively "make up" lies or stories. Which, based on this joke, you probably do as well. Get it? Good.