Why? It's a solidarity thing. Selina answered the call, and it seemed like the right thing to do. It'll grow back, I think. Just in case it doesn't, I'm buying stock in sunblock.
Or as they say:
I've answered the call to be a hero! I'm having my head shaved to stand in solidarity with kids fighting cancer, but more importantly, to raise money to find cures. Please support me with a donation to the St. Baldrick's Foundation. This volunteer-driven charity funds more in childhood cancer research grants than any organization except the U. S. government. Your gift will give hope to infants, children, teens and young adults fighting childhood cancers. So when I ask for your support, I'm really asking you to support these kids. Thank you! Click "Make a donation" to give online, or donate by phone or mail.