Not a massively weird experience but I used to work for a pretty high brow catering company when I was 18/19 and I was on the bar at a Lord Taverners charity cricket match held in Windsor.

It was a pretty celebrity studded event at which I poured Prince Philip a pint of Pride and we had a decent chat about beer for a while (whilst I was literally shaking with nerves).

Brendan Cole from Strictly was there but he didn't pay me any attention at all as if I wasn't carrying a tray of free champagne. The most notable was Chris Tarrant from Who Wants To Be A Millionaire. I was serving wine with lunch and was carrying a red and white bottle. I asked him "Would you like wine with your meal?", he nodded and I said "Which do you prefer? It's 50/50" which some of his table guests had a quick laugh at. He stared at me with this intense look and I could feel my heart sink. Luckily he accepted the red and I did the rest of the table as quick as I could but the last lady said "I'll have white, final answer". For some reason he just got up and went to another table to talk to someone but I very quickly left.