I'm so bummed I didn't ask for her number

I went to the UK a few weeks ago for an academic conference.

I have this habit of brushing my teeth right after eating, so I always brushed after the in-flight meals.

I was brushing my teeth in front of the lavatory as usual when a flight attendant told me, 'Wow, you brush your teeth a lot' lol.

We did some small talk, and honestly, she was totally my type physically, but talking to her made me like her even more.

I wanted to ask for her number, but it felt a bit rude since she was working, so I just hesitated and got off the plane without asking :(

I thought we'd be on the same return flight (I asked when she was flying back but got the date wrong T.T), so I planned to give her my number then. But when I saw she wasn't there, I was so disappointed.

I know she was just being professional/kind because I was a passenger, but I'm just so curious about her... I've been regretting it for weeks now T.T

Even if she never called, I feel like I wouldn't have any regrets if I had just given her my number. It's such a shame T.T...