Sense of smell

So I have aspergers syndrome and one of the conditions is over hyper sense or under hyper sense. I have literally no sense of smell. I can smell if it's really really strong or right under my nose but other than that, I really can't smell much. As soon as I got in the car with my boyfriend today I smelt this really sweet smell and asked him what it was and he told me it was the air freshener then he was like wait is this the first time you've smelt this? I was like yeah. Anyway apparently this air freshener has been in his car for weeks and today is the first time I've ever smelt it. Then I was like are you eating mints? He was eating tictacs and I could smell it. I know it seems like nothing to everyone else but to me this is really strange and a real big thing. I guess my question is why all of a sudden has my sense of smell appeared?