Pain is crashing in the middle of Mullholland by yourself, with no cell reception on 100+ degree day and having to ride home, bruised, battered and bleeding. That's pain.
Overcoming your screaming lungs, your heavy legs and your 190+ heart rate to sprint to the top of the climb in first place is pure heaven. Maybe not at the time but later when you relive that moment it will motivate you and make you feel like you can beat anyone.