I recommend wearing this shirt on a daily basis because you never know who could hold the answer to this deep existential question. Is there a homeless person throwing bouncy balls at you? He could be the key. You just never know.
However, once you have found the answer to this question, you may prefer to wear something a little more practical and less philosophical. In this case, I would recommend:
Again, wear on a daily basis because you never know who may hold the answer.