How do you objectively evaluate your skillset?

This is a somewhat common theme, but I can't think of a discussion which advised how to objectively evaluate skills in contrast to other button pushers.

Last night my wife showed me a bunch of job listings for Google. I scoffed at the prospect, because those people are actually incredibly smart. She scoffed at my not thinking that I am one of those people.

So how does one determine where they lie in the spectrum?