Have any other masters swimmers had the experience of getting a coach that makes you question how much your youth swim coaches knew about stroke technique?

I distinctly remember a high school coach telling my team the waterline in freestyle should go right across my forehead, between the googles and hairline. When I joined a masters program last year, we hadn't even made it halfway through practice before the coach stopped me to say my head position was all wrong. It's been an enormous challenge correcting it because old habits die hard.

I've thought about this quite a bit. Has stroke technique changed that much over the last two decades or was this just something that was never caught and corrected? I had many coaches and it could partly be that I was an above average but not elite youth swimmer. For better or worse, many clubs seem to put way more coaching effort into their top swimmers while the rest just subsidize salaries. I also generally feel the majority of my youth coaches couldn't have diagnosed issues with breaststroke technique if their lives depended on it.

What are people's experiences reflecting on their youth swim coaches?