Is relativity common knowledge?

[The Artist Formerly Known as Hawk]

A lot people probably don't. But then, a lot of people don't know a lot about science in general anyway, and are amazed by the simplest of things nerds like us take for granted.

Next try explaining to them how time is also affected by relativity and watch their heads explode when they realise that this is an actual engineering problem that we had to overcome to make gps work.