Quote 67
Still, I liked my work during those days of certainty. I kept my eyes wide and ears alert. The Brotherhood was a world within a world and I was determined to discover all the secrets and to advance as far as I could. I saw no limits, it was the one organization in the whole country in which I could reach the very top and I meant to get there. (17.199)
The narrator's ambitions have been transferred from wanting to be Bledsoe's assistant to reaching the top echelons of the Brotherhood. A large part of why the narrator overlooks the more fishy and disturbing aspects of the Brotherhood is that the organization provides an outlet for his ambition.
Quote 68
I returned the miniature, wondering what in the world had made him open his heart to me. That was something I never did; it was dangerous. First, it was dangerous if you felt like that about anything, because then you'd never get it or something or someone would take it away from you; then it was dangerous because nobody would understand you and they'd only laugh and think you were crazy. (2.65)
The narrator does not express love for anything because it endangers the very thing he cares about.
Quote 69
Perhaps everyone loved someone; I didn't know, I couldn't give much thought to love; in order to travel far you had to be detached, and I had a long road back to the campus before me. (9.51)
At this point in the novel, love is not part of the narrator's life because he believes it would interfere with his ambition. Later, this turns out to not be the case.