I know I crossed the line when -
I'm hopping to London for the weekend for no apparent reason (to commoners). And no longer ashamed to tell people about my MR / bed hop, nor have the energy to explain.
I'm at my best friend's wedding and all I can think of is hoard as many coke caps as humanly possible.
I no longer get out of bed unless I know I'm earning miles / points for the day.