I used to use the sauna every single day of my life until I was 18 and moved out from my parents (ok, maybe 1 or 2 day in the year there was some reason why we didn't get it warm). God I miss that. That place is sacred to us. And probably you don't even now what real sauna is until you visit Finland, nothing like that stingy feeling when the hot steam first burns you for the first time.
And nothing like that burning feeling when you fall on your back to the Kiuas piss drunk and get the word
Narvi tattooed on your back for a while. (I speak from experience). Or when you run piss drunk to the hole cut in frozen lake and injure your leg in a manner that it looks more like egplant than human feet ( I speak from experience)
And the smell when you have visited the smoke sauna and smell like smoked salmon for 3 days. (Well maybe women do)
When I move out of this studio I'm definitely getting a place with sauna. That cures everything. And will probably get me even more seriously injured.
And yes, people here will go to sauna with all family included, until kids are roughly 11-12 years old. Then it's divided between men and women.