I totally agree that knowing oneself is key to get the best out of us, one must be focused on improving in every possible aspect.
About food, what can I say! In my home we always strive to get healthy food at affordable prices, but it's definitely worth it. Health is priority, and without it, there is no way to get ahead.
Books are another essential item. In these digital times, keeping up the habit of reading is like a respite. I too have invested in good books that help me improve and keep my mind clear and best of all, I also have access to the university library.
When at home, eat homemade as much as possible, and avoid packaged foods.
oh, it's great you have access to the library.