I love books that give us alternative variables to one self in a realistic way. I give you an example, in The Invisible Man, H.G. Wells gives you a perspective of a realistic hypothetical of what would it really be like to be invisible and the problems that would come with it. In Flowers for Algernon, we get a realistic perspective of what could happen if you became smarter and smarter until you were the brightest person in the world, how would you react, how bad is it, and what would happen if you also had the understanding that you were once a dumb person.
The book is very well written and you can see the development in the writing following the story. The progress, no pun intended, is connected to the writing and that is done brilliantly. You feel part of the story. The characters were also great, although it didn't said anything, one of my favorite favorite characters was Algernon the lab mouse. I felt like I understood just by Charlies descriptions and it was easy to understand what the mouse might have been feeling. I loved the ending, it made sense and was not rushed.
That sai, it wasn't my favourite book. Mainly because sometimes it felt a bit outdated, or the lack of characters. I tend to enjoy books with lots of active characters. There is nothing wrong with the story, it simply didn't click the "wow this was amazing" sensation.