>none of the friends I made in my 20s were friends borne of a shared struggle. [...] The city I moved to had a lot of transient worker types moving through them

>none of the friends I made in my 20s were friends borne of a shared struggle. [...] The city I moved to had a lot of transient worker types moving through them so there were lots of events organised by and for expats (perhaps I should call us migrants, as that's what we were). People would turn up to a bar and know nothing about anyone except that we all wanted to make friends, and maybe even hook up. I think this is, in its own way, a kind of shared struggle: meeting with groups of expats provided you with a group that you could bond with over the shared experiences and modern "hardships" of adapting to life in a new city.