It sounds like it was a good idea for this person to disconnect from Twitter if reading and processing tweets was taking up that much space in his head. It sounds like it was pretty unhealthy for him and that he was somewhat obsessed with being involved in some way with what people were tweeting.

That's not been my experience of Twitter, but then I only follow 32 accounts (most of which are companies) and I've never felt like I missed out by not reading their tweets.