Self-Referential Signs

This ... this is just hysterical. A self-referential sign over an escalator, warning you not to bump your head on ... it.

And that reminded me of another favorite of mine ... the "this-sign-has-sharp-edges" sign.

And entirely unrelated, I read an article (Everything you ever wanted to know about C types ... exciting, yeah I know) which had a nice little section on a phenomenon I've had to explain many, many times - to people who should know better. It usually starts because some front-end "programmer", while testing, types in 12.34 into some field that is subsequently stored in a database. When pulling that value back, they are surprised to find that 12.34 turned into 12.339999999999999857891452847979962825775146484375. And then they come to me and complain that the database is "screwing up the numbers". Then I try, in vain, to explain the limitations of floating point numbers, and their eyes glaze over. It's a good article. I found solace there. You can too.