I suspect the facts stuck with you... maybe- like me- you don't remember the rigorous way to derive those facts, or do the calculations those facts make possible... but the facts stick with you.

Even if you did, learning changes a person... by definition. You could forget it all and still be permanently marked by the process of having learned it in the first place.

The act of exploration and learning alters a person for the better, it permanently broadens your view of the world.

If nothing else, you have the understanding that a large portion of reality is knowable- it is both far more complex, and far more simple than most people understand... And that knowledge changes a person, it changes the way they view the world.

Learning does not resolve the mystery of reality... it only makes you aware of just how grand the mystery is.