Something I had been thinking about for a while. If you've ever read Hermann Hesse's Demian, Demian just goes on these massive tangents, hardly giving Sinclair time to speak. I think people are more prone to discussing the content of his speeches, but I think the length of them says something about how much he wants to talk about everything upon finally meeting someone he thinks will understand. It's just an interesting characteristic.
Kind of reminds me when I was younger and used to play Pokemon Black. N has a text speed always set to be one higher than whatever the player makes it, even having a special speed exclusively for him if you max the text speed out in the settings.
I want to say this is indicative of people with interesting perspectives having something they want to say, but I've also met people irl who do this same thing to feign interest, or wise people who can come off as being reserved. Seems to me like it's a matter of author's either wanting to make a character come off as different, or the author wanting to discuss their own thoughts through them with near equal passion.