For the Last Time

We are pessimists. This is proved (see recent post on proved/proven) by one of the most common mistakes I encounter: the use of the word “last” when it should be “past.”

“Last” means last, literally. Use “last” if it is the end of the road, and there is no hope of ever doing/having/being whatever it is again. Ever. If you can safely substitute “final” for “last,” you should use “last.”
He spent the last months of his life with his family.

Use “past” if it is not necessarily the complete and total end of something. If you can’t safely substitute “final,” use “past.”
During the past year, I ate an awful lot of food.
We have reported profits for the past three months.
I have been watching Laverne & Shirley for the past two weeks.

If you used “last” in these sentences, it would mean there are no more years or months or weeks, ever. So even if you don’t plan ever to report profits or watch Laverne & Shirley again, you do plan to have more weeks, months, years in your future. Hopefully. So, please, use “past.”

Shall we make this the last time we discuss this matter?