Doctor Lamar's revelation near the end that a) he's known about Vincent's real identity all along and b) admires the fact that, despite his so-called 'deficiencies' and having to hide them from his bosses, Vincent otherwise has qualified for the space program, all through his solid willpower and his willingness to do whatever it took.
Doctor Lamar: "I still haven't told you about my son have I. He's a big fan of yours. He wants to apply here... unfortunately my son's not all that they promised. But then again, who knows what he could do. For future reference, right-handed men don't hold it with their left [when they are peeing]. Just one of those things." (gesturing for Vincent to hurry up) "You're gonna miss your flight Vincent."