But without taking care, our structure can be too much modified, not in the right direction. Our bad traits of character can be enhanced, some qualities can diminish if we don't take care of it. This is why it is so important to also work "on yourself" during lab experiments.
Sure, the matter "work on us", but not alway for the best. It has also its limitations. It can give us equilibrium, enrich us with what we lacks, but also sometimes giving us too much of an element, of a quality, of energie that we already have in us, and that are still a bit raw maybe. This is the explosion point.
More generaly we could say it is the same with some Schools of Mysteries. They are rarely universal. They rarely go, or integrate another paradigm (vision of the world) in their structure. They are very "particular" in the energy they develop and radiates. This is a bit too much specific. It is a question of Matters Totems and Egregors.
While we work on a particular subject and that we've become a specialist so to speak, it is necessary to understand that the path of others is perhaps equally valid. And this can only really be understood only when there has been a real, deep, broad understanding of the guiding principles of Alchemy.