'Sounds like you did everything right. Except listen to yourself! When you said "But the brakes will be fine like 10 minutes later. "
You're done. Move on. Unless this scenario plays out every time you go to drive the car after it's been sitting. Does it?

After you first drive the car after you've opened up the hydraulic system, you will still have to pump up the system, not just "step on the brakes" with one pedal push.
g/l
-W-