I have read that static damage can occur at voltage levels that humans can't detect, so you don't have to have a big shock that you can physically feel to destroy a part. Worst thing is as BB says it may well not fail straight away but years latter in service.
Indeed BrendanP, "static" only needs to be greater than (for example) Vgs max which could be as low as 10v to cause damage.
Most people think of a "zap" which can be seen, heard and felt but that is NOT the case.
