Go on adult education courses, regularly, even 'hobby' courses and you will see this a lot.
My SIL is a die hard Everton Fan, Season ticket holder, football fanatic, she's also an area manager in banking. I have watched her been 'mansplainsed' at, at lots of events. The same men have discussions with the other men, who usually don't follow the football, but they don't need things explaining because they have penises.
I wouldn't have picked up on this when younger, though, I would have thought I was just being patronised, but there is a gender issue going on.
The Matt Damon/Effie Brown is a good example, but I think that, that is Racial, as well as Sexist.
If you don't mix in unfamiliar groups much and think this gendered stuff doesn't go on, watch reality shows like 'Come dine with me', 'Coach Trip'.
Once you do know the signs to look out for, it's quite shocking how many men, don't like women.
They used to try and say that the burden of housework and raising children wasn't a 'thing' that needed a name, it was just a natural phenomenon that came about.
These 'things' need naming and challenging and that includes general patronising.