B737 Captain reported they had a hard landing that was later brought to their attention as requiring a write-up.

Narrative

Had a hard landing at ZZZ on Runway XX. In short; I was managing a crosswind that ended up being much greater than what I originally anticipated prior to the approach. The approach itself was flown very stable. However In the midst of managing the crosswind and kicking out the rudder; I just didn't do a great job flaring and ended up with a firm landing. I looked at the landing as a for lack of better description just your 'run of the mill' hard landing. Hard; but not hard enough to require a hard landing write up. However; upon speaking with earlier this afternoon with FOQA; the FOQA data said different. The landing did trip the FOQA rate of decent and G parameters. As rate of decent on the VSI is not typically in the scan as you are looking outside during the flare/landing. Also; as there is no G-meter the pilot can refer to; it is very difficult; if not impossible to know if you potentially have exceeded any of these parameters. As such without this knowledge it's very hard to determine whether or not if it's something that requires a write up or not. Accordingly; based on the info I had at the time it seemed to be as I said; of the hard; but not hard landing write up variety. So I did not do a write up for a hard landing. Following a phone call with FOQA this information was only just recently brought to my attention. There was ultimately no damage to the aircraft. But again; given what I did not know at the time; I did not do a hard landing maintenance write up. As such I felt it prudent to follow up the FOQA call with a report.