I Myself, can sometimes talk Me into not riding. To tired, been a long day, knee hurting, etc.....
But if I am scheduled for a group ride, it is planed, set in stone and I always go.
I find I need the club ride atmosphere a couple times a week to push myself and the rest of the week for less straineous rides and me time.
As George Thouroghood says.....when I ride alone, I prefer to be by myself.