This led me to a rather convoluted answer from me about being able to divine one's own innate talents.
My personal belief is that it is frankly impossible to know the limits of one's own ability without testing it. And just because it worked once, is there any guarantee that it will work again? No – but neither is there any guarantee that one will fail.
Of course, there are qualifications galore on such a statement. The state of one's mental and physical health will obviously have a bearing on just what happens. A blinded man cannot see again.
But that same blind man will find ways around his disability that push other aspects of his faculties into regions of accomplishment that would seem inconceivable before. His hearing and touch will develop a sensitivity that will, in many respects, give him much of the information lost with his blindness.
Accomplishment is an endlessly plastic quality. It changes all the time, and it is very hard to judge from within just where it stands. An outsider can look on, rate you using his or her own terms and make a judgement. But it will always be a judgement colored by that outsider's own sense of accomplishment – a judgement that can never be absolute.
So why bother at all? Well, pleasure at accomplishment has to come from within, and the closer you are connected to that, the better off you will be. And everything you do, all the time, is an accomplishment.
I am about to get into bed, put out the light and go to sleep. For me, right now, that is as golden an accomplishment as winning an Olympic medal.