Huh...I don't understand

I was talking to my friend the other day.
Then he was talking about his mid term test, which was an MCQ test.
So he said "Wah lao, I don't know why I backside itchy then change my answer from B to C, turns out the answer is actually B".
Then I was wondering, if my backside itchy, then I will scratch it. Why would I change my MCQ answers because my backside itchy.
Its a rather weird expression isn't it?

Its as if the backside has a nerve that is linked to the bracket and the only way to scratch it is to shade it.

Sometimes the truth seems so hard to take

Some people just can't lead a normal life...there there...