“Having a girlfriend is like playing whiffle ball. Being married is the war in Iraq.” Thus spoke Jerry Seinfeld at the Autism Speaks benefit at Carnegie Hall, where Bruce Springsteen wowed the crowd with an acoustic set. Emcee David Gregory fulfilled his childhood dream by barely getting through a squeaky version of “Twinkle Twinkle” on his son’s violin. And Howard Stern — who banked his fortune before the slide in the share price of Sirius XM — was looking happy chatting with his boss, Mel Karmazin, and Donald Trump.