… then why isn’t it possible for you?
I’m not saying that is possible – I couldn’t possibly know. Nor am I advocating any kind of delusional “positive” thinking where you try to trick yourself into believing you are omnipotent.
But when you watch a concert pianist and you think “I know I couldn’t possibly do that…” you must realise that you shoot yourself in the foot massively. To arrogantly presume that you know for sure everything that is and isn’t possible, and yet… if you were really so smart, why would all these things be so apparently impossible for you?
On the other hand, when you instead think “Crikey, that looks bloody difficult… but I suppose it’s technically possible…” you might not realise it, but the ramifications are very, very different. You have loosened your stranglehold on reality, and opened yourself up to a wider, much more expansive range of possibilities.
You can’t make the impossible possible, but you can stop yourself making the actually-possible impossible.
Do not think that what is hard for you to master is humanly impossible; but if a thing is humanly possible, consider it to be within your reach.
Marcus Aurelius, Meditations (Book VI, 19)