Also went to Caltech, and my progression was the complete opposite. Started out going to every lecture and trying to write everything down, but things just moved way too fast -- I'd write down every word and figure without ever internalizing it, and at the end of each lecture I'd have a crappy copy of the lecture notes and no memory of the last hour.

By senior year, my strategy was: don't write anything down, just try to follow the main thread of the lecture. Then afterwards, go back and read the textbook and take exhaustive notes then. Empirically I learned way more that way.