"History does not long entrust the care of freedom to the weak or the timid" - Gen Eisenhower.
Everything is theoretically impossible, until it is done. One could write a history of science in reverse by assembling the solemn pronouncements of highest authority about what could not be done and could never happen. - Robert A. Heinlein
I still recall a part of that book wherein the kids ridicule their father for recounting how he struck an accelerating and spinning mass with a lever in a one gee field, such being scientifically impossible with human reflexes. The father, of course was talking about hitting a baseball. Just classic.