Interesting choice of worlds.
Think Dorothy Gale.
She had the power to go home all along.
Which is exactly what Kara told him 2 seasons ago when she didn't throw him by his ankles into the stratosphere during that episode exclusively devoted to teaching him how to fly.
I want to discuss what Jor-El meant by "trials".
Is it possible that the boy who could not fly was operating with a net the whole time?
Did kryptonian machinery have it's fingers into the minds of most of humanity to make sure that Clark got training wheels while learning how to stand up to the big bad? Was there no point during the entire run of Smallville that he was ever in any danger and every threat was manufactured and regulated by either his ship or the fortress?
If so, then, every victory was hollow.
And every lesson was pointless.