According to ASAPScience, the world's population expels 70 billion butt burps a day. That averages out to 10 toots per person daily. That's a whole lot of stink going 'round. Now, the reason why we detest other people's gas but put up with our own is simple. Our brains are wired that way.
Back in our caveman days, a fart could have been considered a biological weapon. With no clothes on to contain the contaminants, this fecal spray could have dispersed all kinds of nasty bacteria that would've spread disease all throughout the cave. If early man caught a whiff of his buddies back draft, he would have headed for the hills! So, other people's gas... bad. But our own smell is actually a sign of health.
We've adapted to like our own odors, to help us maintain proper hygiene. We wouldn't be able to take care of our own bodies if we were repulsed by them. Our own farts become familiar to us so we can maintain a higher level of well-being. So, don't worry. Bask in our own glory. It's good for you. And no, we're not pulling your leg with this story. Maybe just your finger.