I live by two simple statements, “No one can make me” and “No one can stop me”. I adopted this some time in my early forties.

This applies mostly to social events and activities.

Want to jump on my motorcycle and head off for a weekend? No one can stop me.

Don’t want to attend a wedding or birthday party? No one can make me.

My time is mine, and I’m free to choose that which I do and don’t want to engage in.

Aside from that, as others have said, you really do stop giving a fuck what other people think of you.

This leads, at least in my case, to a smaller, but far higher quality social circle.