That is so true and reminds me of the programs I've been watching lately where people compete using their psychic skills. I think it is called "America's Psychic Challenge", though was done first in Britain. But I just cottoned on to the program so I am watching the "finals". It is absolutely compelling. And I noticed that some of the participants are able to tap into particular abilities with great ease whilst struggling with others.

For example, one of the challenges was to find in this desert area, a boy who was intentionally hiding. One psychic man ran straight to the boy. Other of the challengers took 30 minutes and whilst close to finding him, did not find the boy. Yet on another challenge the man didn't do as well. Depends probably on many things, how good they feel that day, etc.