The deodorant curse

I don't know if it is common or not, but for me choosing a deodorant is tough. It isn't because I can't find one I like because I can. It is because when I do find one I like, it seems like it gets discontinued soon after. I don't know why I can't find a deodorant that I like that stays on the market. Anyways, the reason I was even thinking about this is because I love when I get or switch deodorant to a new scent. For the first few days I can smell it on me no matter what & it is something that I like. I recently switched deodorants and have been enjoying the new scent but today it disappeared. Why is it that we get used to smells? It's not like the scent is gone, I just don't smell it anymore unless I am putting it on. We even get used to bad smells after awhile.