I am an EE student and I feel a bit confused right now, thus far I've only taken circuit analysis (nodal/mesh/thevenin/transformers/phasors etc) and one semester of E&M. I was taking a look at this http://www.ledsales.com.au/kits/nixie_supply.pdf and I know that is explains the function of the circuit in the document, but it's like I would have no idea how to do this if I had to start from scratch. And, I have an old Radio Shack electronics kit and most of the projects in it make me feel really stupid, I would have no idea how to design a circuit from scratch that has the same functionality. Is there anything I could do to improve my knowledge of circuit design and figure out how circuits actually work? Like in that nixie power supply, if I were just given it and had to determine what it did, I would have no idea what to do. I have access to the Art of Electronics and Sedra/Smith and a circuit analysis book, but I don't know where to start.