Day by day it feels less and less like regular data modeling and more like a debate with Jordan Peterson where you argue for ten hours what a "name" is.
Eventually you end up having to make choices and deal with the consequences. Otherwise Jordan Peterson would have you chasing your tail for days about what a "choice" is, and nothing would ever get done.
tl;dr: just make your best guess and always include an extra "notes" column where things can get leaky.
Not days necessarily, but I think quite a bit of time should be spent data modeling, yes. Before you’ve ever touched the keyboard, it’s very helpful to attempt to model the problem on paper or a whiteboard. You quickly find problems with your initial guess that way.
Notes / data / extra et. al columns are the worst, as a DBRE. People inevitably shove various shit into them over time instead of making an effort to properly fix past mistakes, and at some point, they practically contain their own table.
Eventually you end up having to make choices and deal with the consequences. Otherwise Jordan Peterson would have you chasing your tail for days about what a "choice" is, and nothing would ever get done.
tl;dr: just make your best guess and always include an extra "notes" column where things can get leaky.