As people have already said, i get the sometimes, and it's just my sense of self preservation kicking in... lol
the good thing around where i live is, there's lots of things to do, and with some of them you can perform the same action from different heights/whatever, so if you can build up to something, i find it helps...
Try that with that person if they cant do anything at first, just build it up, step by step...
As my old music teacher used to say as a metaphor 'There's no point trying to run, before you can walk, or you'll fall flat on your face'