Clarke reminds us that impossibility isn't a fixed boundary we discover—it's something we create through our own timidity, then mistake for fact. The truly unsettling part of his observation is that we can't know what's actually impossible without attempting it; caution keeps us perpetually in the dark about our own potential. Consider how every surgeon performing the first successful organ transplant had to operate in what *seemed* impossible, guided only by theoretical knowledge and necessity. The limit, in other words, often sits not in the world but in our willingness to be wrong.