The more I sleep the stronger I get.
My grimoire give me new skills and magic as I wake up every day! Everyone else tries hard to memorise and understand their grimoires and gain new magic or skills, but for me, I get them automatically.
What I get all depends on my luck, but I can easily acquire the highest tier magic. While holding onto the grimoire like this, I enjoy my time in another world with my wife and friends that I've made here.