Why are people so scared to fart?

Farting is a part of us such as yawning or sneezing. It was scientifically proven that the average person tends to fart 15-20 times a day.....if everyone does it...then why try to hide it? Or be so embarred by it? Why can't people just say excuse me and go outside or go to the bathroom to fart? Or even just do it there as long as it is in a decently ventillated area? Why try to hide something that every body does and it is a naturally bodily function?