Normally, reading is a relaxing act. You do it when you're comfortable and the words flow seamlessly into your mind. Yes, reading isn't as passive as say, watching TV where everything happens before you, but usually, it's close. There's even a point when you're so immersed in the text that you can't stop reading. It's one of those moments when you suddenly realize the sun is rising and you're still in bed, reading the damned book.
Not so with Ulysses. Can I understand the individual words? Yes. But the context of each sentences needs some deciphering. Ulysses is probably the first book wherein I thought, my God, this is difficult reading! Of course to the credit of Joyce, it is no exaggeration to say that every word, every syllable in the book has a purpose. Unfortunately, this also means I can't doze off and read... I really need to concentrate on the text and have focus.
Obviously, words can't describe the endeavor. The best analogy I can think of is combining the act of reading with solving a higher math (i.e. Calculus) problem. And there's been lots of times when you simply want to stop and give up. I never expected reading could be such a chore but then James Joyce comes along.
At the time though, I had good incentive to finish reading Ulysses. I had one week and we were having an exam in class about it. Made me want to pray to