How odd. When I use that phrase, I mean it literally.

I've never understood that phrase to mean anything other than its literal meaning.

You must speak some mythical human language that makes sense :P

No way!

Honestly, I'd be interested in knowing which of us is using it in the "normal" fashion. I really don't know. Or perhaps we both are and it depends on the region.

Yeah, it probably depends on a lot of factors, including social sub-cultures within dialects. To me using "I can't remember the last time X" to mean "I actually can't remember X happening" still sounds incredibly weird. Is that what you mean by the literal meaning?

To say the latter in conversation I would usually say "I can't actually remember X happening". I think "I cant remember the last time..." is roughly a shorthand for "I can't remember when the last time was that..." but who can be bothered actually saying all those words :P

Yep, that's pretty much what I mean. I'm not sure whether or not I've ever seen a car run a red light in person (aside from the all-too-common squeaking through yellows), but in any case I can't remember any specific instance.

No time like the present to present the present English that people speak :).