What are your Eureka Moments in this Hobby?

I’ve had two. 
The first was when I discovered “non-horn” speakers. I bought Klipsch Heresy II’s in about 1985 and had them for a long time, and then moved up to the Chorus model. After a few years with the Chorus, a friend bought a pair of Snell C5 towers. Boom.  I bought a pair a week later and sold the Chorus. 
 

#2 was back in about 2000 or 2001. I made a visit to the Legacy Audio factory in Springfield, IL. I heard the Whisper model and had that emotional rush we all look for. I had to have them but at $17,500 a pair, (2001 dollars) I couldn’t afford them. I vowed to myself that someday I would buy a pair. In 2009 I did and yes, still the same rush. I still have them (see virtual system) and still get that same rush every time I hear them. I can’t imagine ever selling them. 

@hifidream Impressive!  My good friend has planar speakers, open baffle subs and Danville processing!  I visited their room at CAF for a demo.  interesting and heady stuff.  Such a great hobby with so many ways to go!  Would love to hear your system (so would my friend!).

For my Eureka moments

1)  listening to well recorded sessions on my LS3/5a and how it presents a very palpable and truly correct tone of female singers or when playing intimate Jazz in a club. a Wow moment and it still does not old every time

2) When I hook for the first time my Pass X150 to my ATCSCM. it transformed these atc into a set of speakers that have been raved by a lot of audio critics. the previous amps where   AHB2's which were not slouch at all, but the Pass took it as a level way above it

I was switching back and forth between my solid state Hegel H200 and my tube CR Developments Romulus Integrateds depending on my mood. Then one day, Eureka!!! The H200 has a Theater Bypass channel and the Romulus has a Preamp out!!! Connected the Romulus to the Hegel and WOW!!!!!! 

The first time I decided to spend $1000 on a MC Cartridge.  Everything changed.