Is Knowledge Really a Recollection?

In the Phaedo, a point was brought up about learning - how it is merely a recollection of thoughts that we already know. In a sense, it's inherent intelligence that we are born with. But I don't see how that is actually the case. Knowledge, much like everything else is ever changing - obviously we have knowledge of things such as murder, etc... - but on the other side, knowledge changes with the environment that it is in.

For instance, if knowledge is recollecting past thoughts or inherited thoughts, then we would be essentially going in endless circles and never resolving from anything. This thought is simple - lets say that we are learning about science. The atom is the basic form of life, a stable factor. But the variable is the environment, and with the every changing environment, how can we be sure the actual form of life that the atom will take on? Obviously this is very complex, and I am getting confused by writing it - but to me there's two main points of this. 1) If knowledge is simply a recollection of thoughts, something that lives on originally, how are we advancing at such a quick rate and why is the idea of "knowledge" changing every day - with thoughts, beliefs, and ideology changing with it. 2) If knowledge is inherited,why do we face reoccurring problems through the world?

Granted this may not have been the intended argument of the Phaedo, but it begs the question of if knowledge is reoccurring, then why do we continue to face the same challenges?