Everyone's in agreement but noone knows why.
Obama: Hey everybody! Vote for me to be president!
Audience: Sure! We'll vote for you! (wait, what are we voting for him again?). I guess it's ananimous!
An unexplained feeling of ecstasy felt for no one specific reason. Opposite of PMS. Sometimes the overwhelming feeling of so many hunky-dory events in one's life. Unbridled individual happiness.
After receiving solid A's on his report card and getting laid by the hottest cheerleader in school, Mike was feeling absolutely ananimous.