I'm in the same boat - closed account with over 100k points!
I only found out when I had a stay and the balance was far lower than I thought it should be.
I'm sure I have a charge at the restaurant of the then Salt Lake City Hilton during the period I should have been racking up points. I just have to find the CC statement and ask them if maybe they'll post those meals as points and give me back my miles.
Jim