Sometimes it is really helpful to just suspend the idea that you "already know" something. After all, the things that seem impossible are generally just things we have not gained understanding of yet. A great example is/was the very certain knowledge that the Earth is a flat surface and that the sun revolves around the Earth (of course the Earth being the centre of the universe). This was scientific fact not so long ago.
Based on this example, I think it's a great idea to suspend "impossibles" and replace them with, "Insufficient information's". In other words, nothing is really impossible, it's only a lack of information or understanding that makes it seem that way.
Even the things you are sure about most likely hold some elements that you only have an incomplete understanding of as well. The only certainty is that there is so much more to know and learn. In keeping an open mind about the things you "do not know" you gain the key to unlock the doorway to greater understandings.
The day I do not learn something new will come as a complete surprise for me!
With love and light