I bought a physical copy of pic related. I often feel it's easier for me to retain knowledge when I read it in a textbook. When I pirated books for uni courses and needed to read more than a few chapters I sometimes printed those.
Did I make a mistake? I wanted to cancel the order, because I got second thoughts (it's rather expensive (for me), even though I made a good deal I think), but I can't cancel it anymore, it will arrive to my place and the only thing I could do is not accept the package when the parcel guy comes to my doorstep, but that would be probably awkward.
Edit: Yes, I do have a pirated digital copy of this book