Went through this a couple of months ago. A combination of factors meant that I’d not been out on the bike for almost a year – change of job, and regular riding buddy being out of action with a ‘hurty knee’.
Six weeks ago, a friend who I know through skiing came up with his new Blur LT to sample some Peak District riding, and I agreed to take him out. We went up the Cut Gate, he loved it, I had a nightmare – sore arse, boinked after about an hour, and my front mech came loose half way back down to Ladybower. However the few bits of downhill on the other side were enough to remind me what I’d been missing, and I’m now out on the bike 4-5 times a week, have bought myself a new bike, and am going to Morzine in a couple of weeks, and am enjoying it more than ever. I’m sat here with achey legs from being at Ladybower on Sunday, Jacob’s ladder yestereday.
I’d say go somewhere new, meet up with some new riding buddies, do something that you’ve not done before. Go on a skills course, or if you normally ride trail centres, go and do an ‘off piste’ ride, or vice versa, and you’ll probably find your mojo again.