Palindrome gurgled happily, sounding much like they were
saying:

Oh come on - are you so perfect that you've never made a mistake about
what speed limit applies in an unfamiliar area?

How would I know? Unless I have reason to go back there again and find
out that I was wrong the first time, the odds are that I would have done
so in blissful ignorance. But, if there is no other traffic, I have to
be really, really sure what the limit is, to go through a speedcam at
over 30.

Oh, gawd... Are you one of those people who brakes from 45 to 25 at the
merest sign of a camera - even though it's a 60 limit?

It's _straightforward_ to know what the applicable limit is. It's basic
information that all drivers SHOULD know at ALL times. If you don't, then
either you really ought to get your short-term memory problems
investigated, or you may wish to drastically improve your observation.