I don't consider any of my past audio endeavors as wasted, it was like a survey course in that I had to learn and experience different presentations to come to a preferred presentation. I've found once you get to a 'certain' level of resolution/ transparency that never fails to engage its all a matter of presentation.
The greatest angst I felt was the years spent in attempting to reach a level of resolution/transparency that was always engaging. This was a real slog in that while I'd at times realize my goals here there was often only temporary bliss. For me there were no short cuts, much time, effort, expenditures, fine tuning, butt in the end I've reached my goal whereas every listening session is a totally immersive, engaging musical experience.
And I'm still not done, I'm now enjoying various presentations via relatively easy rotation of a couple dacs, three amps and two preamps in various permutations. And I"m planning on adding at least one more amp to the brigade, this all great enjoyment for both the audiophile and music lover in me.