1.) It's your bike shorts. Specifically the quality of the INSERT in those shorts that provides seat comfort. Be sure your shorts don't SUCK. Many of the shorts weenies wear do.
2.) It's your position. Experiement with the seat angle and position on the seatpost. Get that equation right and your seat pain may just disappear.
3.) It's your body weight. The lighter you get, the less weight on your sit bones, the less likely you will be to have any issues with seat comfort.
Your number 2 would be my number 1.
I'd add another one: accumulated riding time. I don't know if its from tighter muscle, less weight (less flab) on the butt, or what, but putting in the miles seems to help.
The minimalistic seats I find comfortable today would have puckered my nether reaches in fear a few years ago.