After getting older, I've realized that sometimes people have a lot on their minds and omit the courtesy's sometimes. Guy might have been awake for 48 hours too.
On one two-leg Europe trip, I thought about calling out a older FA for a lack of simple crew courtesy. She kinda of stared and would walk away multiple times (not operational stuff). Glad I didn't. I later learned her husband died suddenly something like 5 days prior. 3 days prior she found out he hadn't paid any life insurance bills and the bank accounts were empty. She had to work the trip to pay the rent (already used bereavement pay for trip earlier).

If you see "Captain Happy" 2 or 3 more times down the road, then he should be a candidate for TOTD. It's rare, but there are still a few of us with the recluse non-social engineer behavior.