Beat the person who once thought this was impossible.

You have already outgrown several of your own certainties about what you could not do. That is worth remembering, because the current list of impossibilities was written by the same person who wrote the last one, using the same limited information.

Recall one thing you now do easily that you once believed was beyond you. Then look at your present list of impossible things with that in mind. At least one of them is probably wrong in the same way.