I feel the same way as you.
They say there isn't a better way to learn than to teach it. Everytime I give you guys some answer or help you out with your questions, I always 'relearn" more and more spanish. You have no idea of how much I've learned spanish during the past 2 years!!!
Same happened to me when I teached physics in a escuela preparatoria (bachillerato) which I think is the equivalent of either junior high or high school in the US. Even if it was 'easy' or basic physic stuff that I learned whilst in high school and the university, I could easily say I learn way more on that semester as a teacher that my whole school life.
We have 2 words that are very similar in spanish, one is 'aprender'- to learn, and the other one is 'aprehender'-to aprehend, to detain , or better "to understand"....and I had a teacher who always said....
"Tienen que aprender a aprehender"-You must learn to understand, or something similar, but playing with the similar words, and in escense he wanted us to 'retain' what we learned and I the same time understand it versus just memorizing it.
During my time at the university I memorized many things (e.g physics or math), some of which i still remember, but some of it has been lost from my mind... but the things I comprehended , understood or taught later on, are 100% stored in my mind.
Anyway, buena suerte, o mejor, EXITO!