What you encountered was a sociopath projecting how they feel about every action they take onto you. Somehow you are the asshole for not complying with their selfishness.

I’d even go as far as to say that everything I’m not forced to do is, (very) technically, more or less, based on selfishness/egoism.

• There’s the times when I genuinely enjoy doing something
• times when I don’t really care about something (or even dislike it slightly) but friends/family members are happy to do it together (in turn being beneficial for me because I like them being happy)
• something I may dislike but is (in the long term) beneficial for me (studying, taking yucky medicine :)) )
• probably lots more categories I can’t think of/don’t have the time to write down

Of course this is kinda taking it to the extreme, but I don’t think I’ve ever done anything without any benefit, however broadly defined, for me, unless I was absolutely forced to do so without any way out.