[redshirtrob]

This drove me crazy too. I do not know anyone who conspicuously takes a long time to learn something, and then claims it's easy. In fact, it's quite the opposite, as you mentioned.

Now, I have observed cases where someone inconspicuously took a long time to learn something and then claimed it was easy. This was more to elevate one's own intelligence in the eyes of another. As in, "Wow, this is really hard, but Joe said it was easy. He must be super brilliant."

The other prevalent case of this behavior is when reading mathematic proofs. Often times you'll run across a statement in a proof along the lines of: "It's easy to see that X is true," for some statement X. But, X is always an existing result, and so this is really a way to focus on the details of the proof at hand and not get bogged down in proving every single non-trivial step.

In fact, when I was a Mathlete, our coaches instructed us to make use of this approach, even if we weren't 100% sure that X was true. If we were pretty sure X was true, but we couldn't remember the proof, and we knew it would take prohibitively long to derive the proof, then we would make the statement.