Interesting - I don't know about the maceration theory, but I've heard too that some perfumes change over the course of the first few months from production. Perhaps you just got a very new batch.
Of course, over time, when the alcohol evaporates, the juice inside become more concentrated, some top notes evaporate, and the smell is richer and deeper. But I think it takes years for the process, plus, it would be evident from the bottle how much has evaporated.
2 seems unlikely. Too short a time, unless you kept the bottle in full sunlight. Even so, when a perfume goes off, usually you get off smells (cardboard, vinyl, etc), not pleasant ones. 3. can be a part as well, as for food, we get used to intense flavors. But again, usually I think the direction is the opposite: that is, what felt strong before, now feels weaker.
Temperature could occasionally be a factor too. With heat, things evaporate faster; some molecules which are not evident in low temperature now become more noticeable, and this happens earlier on in the development of the perfume.