When Zak called to say he'd gotten into flight school, Lee put on his best supportive brother voice and got appropriately excited for him. He didn't ask Zak if he really wanted to be a pilot, or tell him that the only reason they'd agreed to take him was that the well-known and well-respected Commander Adama had asked them to. He said, "Congratulations" and silently begged the gods (more out of habit than faith) to keep Zak safe and not let him fail. He didn't let the part of him that thought it would be better for Zak to fail basic flight so he could let go of this flying thing get a word into the prayer.
Later, as he climbed into his Viper, Lee stopped to wonder if he was doing the same thing as Zak, convincing himself he wanted to be a pilot because he didn't have much of a choice. He'd decided long ago, back in his days of hero-worshipping his father, that he wanted to be a pilot, and he'd never really questioned his motives. Maybe he was deluding himself as much as he thought his brother was.
He took off then, the walls of the launch tube speeding past, then giving way to the blackness of space. He turned, one of those smooth, almost instantaneous turns that only a Viper was capable of, and saw Caprica spread out blue and green and white before him, looking deceptively pristine from this distance. Then he flipped and flew off into the blackness and thought that it didn't matter anymore why he'd decided to join the Fleet. This was what he was born to do, not because of who his father was, but because he was made to fly.