What 6shooter said... tell them exactly what YOU feel, even if it's "b/c I want to". You're an adult, you make your own decisions for your own reasons. If your parents can't understand this... that's just too bad aint it? And on a seperate note... what makes your father think millions of people aren't already carrying guns everywhere? Do you think gang members care about getting their CCW??? People will already shoot you for looking at them wrong, but now you can shoot back. Don't be fooled into thinking the only way people carry firearms is through CCW. People will do it no matter what the law says... if they didn't, we wouldn't have created the word "crime".
I believe in this:
"An armed society is a polite society. Manners are good when one may have to back up his acts with his life."
-- Robert A. Heinlein, Beyond This Horizon, 1942
I always have, even as a youth... and even more as an adult.
For those who fight for it, life has a flavor the protected will never know.