There is a cure though. Unfortunately (for some) that cure is to just get on and do it!
This 'idea' was a bike ride (no surprises) - or to put it more specifically; two bike rides joined back to back.
People often commit themselves to the famous British Heart Foundation "London to Brighton" route, or to the lesser known BHF "London to Brighton OFF ROAD" route.
I had it in my head to do BOTH, in one go! About 135 miles. Hmm....