Many years ago, possibly even before FF programs existed, I was traveling with a boyfriend from Boston to Paris. I think we checked in late enough so that our seats together had been given away, or maybe we didn't even have seat assignments. Bump up to business. Wow! Reclining seats with footrests, amenity kits, champagne, cognac after the (relatively) lavish meal...and the morning after, the very worst headache (i.e. hangover) I've ever had before or since. I've had a handful of op-ups since but you always remember your first time, for better or for worse.