I must have been around 8 or 9, sadly under the impression that only boys farted. I guess it was a guy thing. Girls did not burp or fart, somehow they had been trained to suppress these functions.
So I am sitting near the fence that separates my back yard from the house behind mine. Quiet, introspective, when I hear some giggling. Seems the neighbor girl had some friends over. I listened, curious little george that I was. I heard them talk about some of the boys I knew, some I didn't. After a few minutes I heard one girl say to the group "wait....here pull my" and before she finished the statement, this little girl blew out a tire popping fart. The group of girls just broke down laughing so hard. I was in shock. Never before had I heard such a display of macho behavior in a girl. This moment caused me to think what else do girls do when boys aren't around.