1968. Heard a truly full-range system. Wow! Bass really helps hifi sound like music!
1989. Heard (and bought) a pair of Apogee speakers. Understood "transparency" for the first time.
1991. Heard really good digital (dCs) at a show. Found one could have zero flutter and non-irritating violin sound simultaneously.
2005. Started treating my audio room (per ASC plan). Suddenly, everything sounded better.
2006. Started using subs and DSP to get even bass. Bass without boom: a pleasure.