Various smells remind people of drugs all the time. Memory has a very powerful association with scent, so if you smell something even remotely similar it can instantly remind you of the drug. This has happened to everyone I've talked to who has used a certain drug with any regularity. It can also be kind of a trigger for people unfortunately. Just as one example, I went through a period (many years ago) of using matches when cooking heroin and now every time I smell a blown-out match it totally reminds me of heroin, it's like I can even smell the cooking heroin.
It is also possible that, as Fire&Water suggested, the meth you were using may have had some coffee in it. But it could also have been the smell of the cleaner or the machine.