Time & Space:
There is so much space to cache and so little Time!
Theory of relativity informs us that time and space (The where and when) are relative to gravity and movement. I can never seem to defy gravity with movement and cover enough space in the least amount of time to reach all the caches that are planned. perhaps if I had an H.G well's time machine I would be FTF on all the caches.
Alas I will have to use my limited time to cover as many caches as soon as possible if not possibly sooner!