While I like it, I have quickly gotten tired of the constant iterations of "why?" (sometimes with the subtext of "you must be crazy," sometimes just out of curiosity). I have yet to come up with a response that accurately conveys my feelings about the question; it does not cease to amaze me that I'm expected to justify with some especially persuasive reason why I would shave my head; no one would ever bother to ask why I decided to get an inch trimmed off. To me, it is very nearly the same question: it is hair either way.
Lately, I'm tempted to start quoting Merchant of Venice at them; Shylock's speech in Act 4 scene 1 is an accurate and eloquent answer to the question of "why":
. . . I'll not answer that:
But, say, it is my humour: is it answer'd?
What if my house be troubled with a rat
And I be pleased to give ten thousand ducats
To have it baned? What, are you answer'd yet?
Some men there are love not a gaping pig;
Some, that are mad if they behold a cat;
And others, when the bagpipe sings i' the nose,
Cannot contain their urine: for affection,
Mistress of passion, sways it to the mood
Of what it likes or loathes. Now, for your answer:
As there is no firm reason to be render'd,
Why he cannot abide a gaping pig;
Why he, a harmless necessary cat;
Why he, a woollen bagpipe; but of force
Must yield to such inevitable shame
As to offend, himself being offended;
So can I give no reason, nor I will not . . .
Unfortunately, even if I managed to recite the whole thing, I would still get blank stares.