Interesting. Strange but possible. Sensitivity to certain musks is very personal, though usually perfume house should make sure to include several musks so that everybody can smell. The old one, though, was considered strong by most people, so a change in formula must have taken place.
Usually the stronger something is, the quicker olfactory fatigue kicks in. That's why you have to be VERY leery of people who report 30 minute longevity on a scent. It's more than likely olfactory fatigue. I'd say in 90% of cases, that is the issue.
The other thing is people spraying scents too close to their nose. The stronger the scent, the less sprays and the further from your nose you should spray to maximize your own ability to smell it.
If OP is talking about Amouage Epic, then yes, it is a funny one. Doesn't smell strong sniffed from the wrist at times, but is actually room filling if not applied moderately. I have read many conflicting opinions on its strength and formulation. some say the bottled juice isnt the same as samples. Be not deceived. Epic is no wimp.