I try to imagine wind as a liquid flowing through and across the mountains - I find it makes it easier to imagine where the updraughts and downdrafts will be and where you are likely to get rotors.
I personally haven't ever heard of a structural failure to a helicopter due turbulence but I remember reading an article once about potentially overstressing helicopters because they feel as if they handle turbulence better than light aircraft.
I guess the answer is quit before you get frightened?