I agree! It started when DH and I got upgraded with miles to Business Class on the way home from Edinburgh in October, 2001. Yeah, nobody was traveling so we were able to do that. He was over 6 feet tall. Not sure if it was the nice, big seats, the refills of Bombay Sapphire or the made-to-order ice ream sundaes that hooked him, but after that we used miles to fly in Business if we could. We eventually quit using Coach on long hauls- just took too long for him to get back to normal.
Now that he's gone, I still fly Business Class. It's only half the cost if just one person flies. Who knew?
I've started dating again and I've joked that one requirement for a new man is that he can pay his own way in Business Class on long hauls.