Many years ago I (literally) bumped into Sam Neill in a Qantas Pub. Small spillage of his wine and a red face for me, but spent a really nice couple of minutes chatting with him. A gentleman, indeed.
Have also sat across from Ross Kemp in the KF lounge - looks exactly like himself (go figure).
Mark Webber (twice). Once before he got into F1, but after he flipped the Le Mans Mercedes on the Mulsanne straight - described it brilliantly for me on a walk from our SYD-MEL plan to the carousels (incidentally, I sat a few seats away from him and he spent the entire flight with his head resting on the seatback in front of him - hectic schedule I imagine).
I then ran into him in the SK Business Lounge departing for SYD after a Singapore/Malaysia holiday with all 3 of our kids - the kids were gobsmacked (yes, they knew who he was). This was a year or two after he quit Red Bull.
On the flip side - on the 600 or so other trips I've taken, I've met more nobodies who've been wonderful in one way or another. Some people just leave you feeling a little more enriched by their existence (no I have not been drinking.......but good idea!).
Hope everyone is well!
Pete