I'm not even factoring in (yet) the tendency to hint for us to vacate by leaving the check before we've finished eating. This has become the rule rather than the exception.
I have the opposite problem! It drives me nuts when the server comes and clears our plates and then leaves us sitting there waiting for the bill for 10 minutes, especially if it's lunch as I'm usually in a hurry.
About a minute after the last plate is removed from my table, little tip meter appears in my head and starts to drop at an increasing rate.