Last year my stepbrother, at eleven years of age and with zero familiarity with the setting, described a 40k Imperial ship as "a mix of Mad Max and Star Wars."

That's the best description of 40k I've ever heard or seen.

Do you have concise descriptions of 40k to outsiders to share? Perhaps coined by you or invented by people who doesn't know 40k? Or maybe some fun anecdote? Please share!