This is also my sentiment.

I am saving up to retire early. If I mention this to friends, most look at me with big eyes and ask “But what will you spend your day on then!?” in a sceptical tone.

I imagine they think I want to drink beers and play golf all day every day, or something like that.

I’m a bit heart broken, that so many of my friends cannot imagine being masters of their own time, without thinking it would be bad for them and/or unproductive.

I think that's the one silver lining of the pandemic's lockdowns; some people were at home again for extended periods of time, finding themselves with a lot more free time and in a place that wasn't just for eating and sleeping.

Yea I've noticed this is the singular difference between those that enjoy early retirement and are successful doing it and those that aren't. Many ambitious people end up wrapping their entire identity up with work and feel completely lost with that gone. It's why so many successful founders throw themselves into new startups right after an exit, despite having way more than enough to retire. Personally, I've taken some time off since selling my startup and I've been so busy learning new things and building new hobbies that I can't imagine going back! Maybe I will one day, but it will likely involve something I've learned from during this time

Why? Why can work noy be your retirement plan as well? I have benefitted a lot from professors who have kept teaching (voluntarily) till physically possible.

Yes. People are so much more enjoyable and interesting when they have a life, go out, have hobbies, do things a little different to everyone else.