The biggest books I ever bought were those on molecular biology and biochemistry. Huge and weighing several kilos. Until then I did not know that it was possible to produce such large paperbacks at all. Some of these books are also among the best I have ever seen in terms of design and didactics. This is also necessary because the area is so big that you can easily spend several lives with it.
I agree with the author that molecular biology is neglected in school or is often not taught in a very motivating way. But this is true for many fields of knowledge, not only for molecular biology.
My entry into the field was when I did a PhD in molecular biology and biophysics after ten years of professional experience as a computer scientist. That was almost twenty years ago now, and I still have the feeling that I'm only scratching the surface.