It (the pre-existing soul) is also part of LDS religious beliefs. Not a path a faithful Catholic would want to go down.
We are humans, living in a world; we experience almost everything in terms of time. Time is a measure of change.
As God is unchanging, and outside of time (there is no such thing as time with God; all is present), when we try to speak of God, we do so in the words and images we know and understand - those of time and change. Right there we have a problem, as we are using “time” language to describe something which has no concept of time. When, however, we try to ascribe something to God, we are too often stuck with our “time” language, which does not adequately express what we are trying to say about God.
As God is outside of time, and therefore, all things (events, if you will) are present to God at once all together, then we can say that God knew us “from the beginning”. But with God, there is no “beginning”, as all is at once present to Him.
So when we read Scripture, we need to remember, when Scripture speaks of God, that we can end up “anthropomorphising” God, as if He were some person in time with us, as if He were “learning about us” as we aged. Not so. Scripture speaks truth (and Truth), but we can easily fall into a trap of putting God “into” time, as if He had a past, and a present, and a future. God has no past, present and future; He revealed Himself as the great I AM to Moses. Alas, Scripture, and human language, is constrained to use the words and concepts we know - which are “time” oriented and related, in trying to speak of something that is not time related.