Users will typically fall into one of the three categories: expert, amateur, or drop-out. The drop-outs decide that during that "I suck at this" phase, it isn't worth continuing. They give up. The amateur made it past the suck threshold, but now they don't want to push for new skills and capabilities. They don't want to suck again. They'll never get past the kick-ass threshold where there is a much greater chance they'll become passionate. (Taken from How to be an expert.)
