Have you "lied" to yourself?

It is time for the utmost honesty. How many of you have made a fairly costly upgrade/purchase and weren't able to hear any difference (even if you struggled, it wasn't very obvious), but convinced yourself the difference was there (to avoid feeling embarrassed/taken, or facing that you don't have "golden ears")?

There's no need to mention the brand/manufacturer, but do mention the type of component as it would be interesting to see whether this type of thing happens more often with preamps, amps, cables, or sources (I doubt it ever happens with speakers).

I'll start. I'm guilty of spending about $600 upgrading speaker my cables and couldn't hear much of a difference.
I've upgraded cables a couple of times and usually could hear the difference but not always for the better. Cables are system dependent--so more costly does not necessarily mean better sound. Don't think I've "lied" to myself--or to the people I've sold them to. They were good cables--just not in my system.
let them break in and then remove them, I often put pieces in my system that I do not think are worth the money until I take them out and hear it without them
I agree with Mkaes. Aside from speaker upgrades that I have made, I have never really noticed big differences until I have taken OUT the new components and replaced them with the old. It's always so profoundly disappointing to spend several thousand dollars and not notice a difference right away.
I bought one of those "noise killers" that you plug into any outlet and it supposed to reduce line noise. Well, maybe I didn't have any line noise to kill!? But for wasting $300, the line noise from my wife was deafening.
There's no need to feel guilty about it. You spent the money and it didn't work out the way you hoped.

I have spent money on amps and speakers that didn't work out. Items have been or will be sold.

What I did learn was it helps to buy used. Your financial hit is much less if you need to sell the item. Also, in-home trials can prevent the purchase in the first place.

So, do the proper break-in with your cable. If it doesn't make you happy then sell it and move on.