This happened to me back in the 1990s when I was assigned presenting Boltzmann machine to the class. I read up on it naturally, could explain each step in isolation but couldn't still quite internalize how it all came together. But as I was presenting it, all suddenly clicked into place. It was remarkable transition from loosely connected foggy concepts to instant clarity which made me break mid sentence. Once re-composed I couldn't help but notice that the manner of my presentation has changed.

The professor (strict uncompromising man hated by most of the class) then remarked, "now I see you really figured it out".