A feeling of complete and utter euphoria which peaks when climbing into bed at the end of an 18-hour workday, a long road trip or hours of extremely strenuous physical activity. Under perfect conditions, the physical release has been likened to that of an intense sexual experience.
It was a three hour drive in the middle of the night, I could barely stay awake. When I got home, I climbed under the covers and had a ten-minute bedgasm.
John: "Dude, that Batman movie last night totally rocked my world! I felt like Christopher Nolan was blowing my mind with his brain baby the entire time!"
Neil: "You, sir, have achieved the Batgasm."