Consider a traditional scenario: A student is thinking of pursuing accounting. That student spends 3 years on a degree, gets their first job, sits down, and realises they'd rather be in a different profession.
Now add recon to that scenario, the student tests the water of the career path before committing with an early internship. Even when it doesn't work, a lesson is learned, and it is hugely valuable for the student and the business.
So, back to the initial question,
Why do we learn?
Perhaps a more apt question is this:
Where do we learn?
To recon, the answer is clear. We do not learn everything that we see or hear, we don't learn everything we read in a book. We learn where we are interested in learning. We learn where we want to. We learn where learning is real.