I can't tell you how many times I've heard, "I'm keeping this bass/guitar forever, so I'll do whatever I want to it to make it mine, and since I'm not going to sell it, I don't really care about the resale value." And then they get married, need a transmission for their car, decide to quit the band, want to take a trip to Hawaii, need a white one to play in the P&W band, yada yada, and there it is, on Reverb or Craigs.
I've gone to see prospective guitars only to find out that the owner wanted a "VOS" finish, so he took a scotchbrite pad to the whole guitar. He didn't bother to remove the hardware, didn't...oh, you know. It looks like crap. It takes a few minutes to screw up the guitar and hours of work to get it back (assuming you can). I've actually purchased two of them that were done this way, and ONLY because they were extremely difficult to find examples of that particular guitar. I'm done with that, however, and after painstakingly returning those guitars to good condition, I'm unlikely to wade into another one. And those guitars were purchased at a significant discount below their value if unmolested. Much whining ensued from both of us during the purchase discussion.
My wife has observed my guitar accumulation (it's not a "collection") and will occasionally suggest that I take the time to put a piece of paper in each one telling what the hell it is with an approximation of its value. I resist because I know that's just fodder for the divorce lawyer, but if I don't, I'll be spinning at high RPM in my grave if she sells them off cheap after I'm gone.