Having grown up mostly reading library books, I never really developed a habit of marking up pages while I read; the most I might do was copy down a particularly nice quote. (I still have notebooks full of these passages, a testament to the hand cramps I suffered in pursuit of the #aesthetic
and need to update my Tumblr bio weekly.)
I think the first time I had to annotate my reading — because let’s face it, I don’t like change and will avoid it unless acted upon by an outside force — was for “close reading” in high school. This may have been Cyrano de Bergerac or it may have been Shakespeare, I don’t remember anymore; the point is that once I adjusted, it would not be an exaggeration to say it totally changed the way I think about and approach reading.