KingTermite 

Just force yourself to use lower gears. It will come natural after a while.

I kind of got a friend into riding about a year ago. He commented once while rode that he was perplexed by my riding style. I rode slower than him, with a faster cadence. He said I was slower, but steady....it seemed like I never let up. He would ride harder and faster, but have to stop and rest/coast for a while. Then at the end of a ride he would be pretty tired and I'd be mostly fine.

I tried explaining why lower gears was better than mashing and even pointed out his pains to create some validity, but he never did quite "get it". He couldn't understand why his "faster" riding wasn't better. Now he doesn't ride anymore....probably got tired of how tired and achy it made him.