I think variety helps.

When I was flyingto IAH regularly, I found repeated trips in CW very ordinary, although the odd Op-Up helped alleviate the boredom.

I tried alternate routings and airlines and that spiced things up. So instead of the same old same old on BA, I tried MAN - ORD - IAH with BD, GLA - EWR - IAH on CO and GLA - AMS - IAH on the KLM Privatair 737.

Apart from the BD flight (which I really liked), the others put BA CW into perspective and I started enjoying it again, at least fr a few trips.