brainteaser

ok so maybe im gonna really embarrass myself here, or rather undoubtedly going to embarrass myself but i dont really care...soo....ok while driving sometimes i decide that ive got my bra hooked too tightly and so choose to loosen it (yes while driving) so here is my question why is it that at any other time i could do this within 5 seconds but when driving it inevitably takes me three years and a day and thats if im lucky? why does it become that much of a challenge? ah well...one may never know.