[Patient0]

This. I remember forking out... $50?... to buy the Commodore 64 Reference Manual from a specialist bookstore (we had to drive there). I was so excited when I brought it home and could finally write programs in assembly (to put sprites on the border using raster interrupts!).

[commandlinefan]

I bought a book on assembler and was heartbroken when I realized I had to buy an actual assembler before I could run the programs.