I'm an avid tyre-pressure checker, but never bothered to check the spare. Too much effort. Today I did, and it was down at 24psi. I've driven 60,000kms and still haven't had a flat... but at least now I know my spare isn't flat!

Of course, don't do what I did, and drop the valve cap between the wheel spokes. It's a pain in the arse to have to take the whole wheel out just to get the little cap...