If you can’t figure out your purpose, figure out your passion. For your passion will lead you right into your purpose.
There are three classes of people: those who see. Those who see when they are shown. Those who do not see.
As far as intelligence is concerned, I have personally concluded that the ability to change one’s mind is the highest form of human intelligence; fundamentally, the ability to recognize that one can be wrong; that is what I call intelligence. This is the best brain-training I can recommend as a former Mensan: to try to keep an open mind.
Use what talents you possess; the woods would be very silent if no birds sang there except those that sang best.