You do not really understand something unless you can explain it to your grandmother.

- Albert Einstein

"The problem with quotes from the internet is it is hard to verify their authenticity"

- Abraham Lincoln

Totally worth a T-shirt

http://www.cafepress.co.uk/cp/customize/product2.aspx?from=C...

It does not then follow that when someone refuses to explain something to you like you are their grandmother that they do not really understand what they're talking about.

Also I'm pretty sure that's Diablo Cody's quote, not Einstein's.