All of the above.
Earlier this year, I met a great group of guys that took me and my son in for a daybreak set at their site on public water. Never met them before, sight unseen, they gladly offered up personal equipment (lesson learned: we didn't bring our ski stuff on our trip), pulls on multiple boats, and the familiar companionship and support that I've seen in skiers everywhere.
I was in one of the boats between sets with one of our new friends (68 years old and still running passes in the course) and I said "I don't really know exactly what it is that makes this so commonly addictive". He swept his arms out and said "It's all this!"
Well worth getting up at 5 am.