Quote from: MainMan79 on October 12, 2024, 02:02:12 PM

Seed phrase: I'm an idiot who sometimes doesn't remember very basic things. I'm fixing my life, but I may need therapy in the near future. Some 6 years ago I changed a Bitcoin Core password hastily, thinking I remember the new password; and forgot it (over 0.6 BTC there to this day, and likely forever).

Insight is one of first steps towards improvement. I would also recommend to learn some Bitcoin basics at https://learnmeabitcoin.com. You can scratch only the surface if you want or you can go very deep the rabbit hole. Depends on you and how much you want to learn and know.

Based on your sloppy handling of passwords and mnemonic recovery words for backup, find a decent quality notebook of a smaller size (because you can hide it better depending on your living situation) and start immediately to write down such things in that notebook. Manually, analog, no digital screenshots or whatnot on your online digital devices.

Your issue with the lost Bitcoin Core wallet encryption password or passphrase might not be a lost case if you remember partially how you constructed your passwords. Many people have some common schemes they think are good (rarely are actually good, but that's another story not to tell here). If you have enough clues for bits and pieces of your password, it may be feasible to brute-force it in an intelligent way. There are clever tools for this, but the learning curve is steep, if you want to do it yourself.

Allow me to quote another reputable forum user:

Quote from: LoyceV on October 01, 2024, 07:31:45 AM

Talk to Dave: Bitcoin Wallet Recovery Services. And watch out for phishing sites!

Dave's recovery services will cost you 20% of your wallet's value and he charges only in the case of a successful recovery, zero otherwise. Fair enough, possibly having 80% recovered is better than 0% sitting unaccessible forever.

Quote from: https://www.walletrecoveryservices.com/pricing/

Our standard fee is 20% of the value of the wallet, only if we are successful. Zero otherwise

If your wallet is valued over $100K USD, then we offer a lower fee of 15% for an initial phase of tests.
(generally takes around a week).

Quote from: https://www.walletrecoveryservices.com/limited/

Limited Wallet Information

Background

This page describes how to get limited Bitcoin-Core (or Litecoin / Dogecoin / etc.) Wallet Information for Wallet Recovery Services (so that we cannot steal your bitcoins even if the wallet password is found)
...

But this is another topic and I digress a bit here. Don't put up too high hopes because succesful password cracking heavily depends on the length and complexity of your password and how much good clues you remember what could've been bits and pieces of it. Dave has expertise and heavy compute gear and he will be honest with you if a recovery attempt is feasible, because he does the heavy compute lifting upfront, no prior payment required.

Quote from: MainMan79 on October 12, 2024, 02:02:12 PM

I downloaded electrum walleet on my laptop exactly 1 week ago. I had payments come in during last week. I didn't realize 'seed phrase' even applies here. I didn't RTFM. I was 100% sure that the password - WHICH I THOUGHT FOR A MOMENT I HAD FORGOTTEN BUT ACTUALLY REMEMBERED!!!! - is enough to own/move my funds as I please. I changed my wallet password twice. From the original, to a new one, back to the original. It worked. Phew, right? WRONG!

Maybe you downloaded Electrum wallet software one week ago, but your screenshot says clearly that you created a wallet in April 2024 and your Electrum used that wallet from April, likely because its name wallet_1 is the first default name and you kept all the Electrum settings as before.

If this wallet file wallet_1 was the last one used, Electrum will try to open it next time you fire up Electrum.

How disorganized are you, sorry to ask and emphasize it? You're dealing with value, with money, with crypto coins worth a considerable amount, like your ~0.6BTC in your Bitcoin Core wallet where you fucked up the wallet encryption password by not writing it down manually in a safe notebook for such important details. Wake up!

I know Electrum quite well, not every detail here and there, but when you create a wallet, Electrum gives you 12 mnemonic recovery words which you have to write down, because you will need the exact sequence of 12 words to confirm you backed those up. Electrum will need you to enter those 12 words for confirmation, no bypass possible here. And only people with photographic memory could possibly replay those 12 words without prior manual backup. (Digital backup by screenshot is plain stupid and a recipe for later desaster. Never do this, you will understand later, maybe.)

Quote from: MainMan79 on October 12, 2024, 02:02:12 PM

I DO NOT BELIEVE I WAS EVER ASKED TO CREATE/REPEAT a seed phrase last Sunday (it's possible that, an idiot that I am, I forgot 5 minute after I did it, because I'm always doing 3 things at once).

Based on your screenshot of your wallet info, you didn't create a new wallet_1 but used a wallet_1 that was created in April. You can't have forgotten the 12 recovery words, because it's highly unlikely you memorized them immediately without writing them down, or god forbids, screenshotted them.

In crypto coin space I recommend to do one thing at a time well and thorough! You have to pay attention to details. Or you risk having reasons to cry...

On what OS do you use Electrum? Maybe it's worth to peek to Electrum's default wallet folder location to assess what wallet files are there.