Guys, why would a boyfriend seenzone his girlfriend?

infpbutterfly
First off, I want to get some things clear:
* I am not bothered by him reading but not replying to my texts.
* He is a very good boyfriend, he cares for and respects me and treats me well.
* He eagerly participates in our conversations and does not seenzone when I ask or say something important or directly related to the topic of our convo.
* In my previous two relationships, which had for the most part been online relationships, online conversation played a huge role and I was always upset if they took a while to reply, did not reply after seeing my texts or did not text me as frequently as I did.
* In my current relationship, we meet mostly regularly, excluding holidays (high school)
* From the very beginning of this relationship, I was never bothered by him not replying on time or replying late after reading my texts. Mostly because I know he loves me and I'm secure in this fact.
We have been together for 10 months. So what I would like to know is, from a guy's perspective, why would a boyfriend who loves his girlfriend seenzone her, or go offline after reading her text? I want to understand this so that I do not end up being clingy or desperate and I'd also love to understand his thought process better.
Guys, why would a boyfriend seenzone his girlfriend?
5 Opinion