I'm still irritated by this! I had an interview a couple of weeks ago for a fairly niche role, not too many people would have my experience in so I can't imagine there would have been tons of other candidates.
I wasn't over confident going into the interview as I wasn't entirely sure I wanted the role but it went much better then I expected, really seemed to gel with the interviewers and they were hugely positive about me so much so I came away thinking I'd be offered the position (which is a big deal for me as I am a very pessimistic person normally).
Annoyed as I let myself get carried away, imagining myself in the new role, getting excited etc only to get the dreaded call that I hadn't been successful (but was given loads of positive feedback about how close to being successful I was).
I'm feeling really flat now and also annoyed, why be so positive and give one impression if they had no intention of recruiting me (and I know I was the last interview of the day so it's not as if a surprise candidate would've blown their socks off after me). I'll get over it but it's knocked my confidence and I just wish they hadn't be as enthusiastic during the process so I would've been more prepared for the rejection 😟