I tend to smoke various things, and have always wondered why I cant smell the smoldering smoke. IE, if I smoke a Black and Mild, I can hardly smell its sweet scent after the first puff. However, if someone else is in the room and lights one up, I can smell theirs for the entire duration. Is this just me? If not, whats the deal? Does the intake of smoke numb your senses? If thats the case, why doesnt a breath or 2 of second hand smoke numb you to what theyre smoking?
Well, it’s not just you: I can’t stand ANY kind of smoke at all, unless I’m smoking also. I have smoked out of self-defense many, many times, lol. Although, if there’s not a breeze and my own smoke wafts back to me, I can’t stand that either, so…I am a hypocritical smoker. 
I’m pretty certain it’s due to olfactory fatigue. As to why you can smell second-hand smoke for many minutes while firsthand smoke seems to lose it’s smell after only a few puffs, I assume it’s a matter of concentration. Inhaled (or puffed) smoke will immediately saturate your olfactory system, and as a result your brain quickly decides to ignore that stimulus (“Ok, I get it. There’s smoke in my mouth. Moving on…”) whereas the lower concentrations in secondhand smoke take longer to saturate your sense of smell to that point.
Right. And, smokers often can’t smell that they reek of stale smoke, and often also pour on the aftershave, etc as their olfactory nerves are so deadened.