This may sound very specific but maybe socially awkward people can relate ?
Basically I've been in the same class (a professional formation) for more than a year and I haven't made any "friends" for the moment (because of shyness)
And then I saw that someone who arrived like a few weeks ago has already made friends : being close to some people, hanging out with them…
I'm not jealous or anything but realizing that hurts a little