I only experience forgetting the pin and the password of my blockchain wallet because i have never opened my wallet since the year of march 2019 until august 2019 that i have been holding and waiting for the price of bitcoin to increased that time. Good thing i saved a document that i enlisted all of my password in my social media accounts, email account, and wallets.

Fortunately, I never lost my Bitcoins. I do not store my wallet in one place, I have many reserves. Which I advise everyone to do.

I kept some of my coins on a local exchange and they had a bug where one of the users logged in and saw that his fiat deposit had multiplied. I think the comma was wrong. Anyway, had deposited 10k and the balance on his account was 1 mill, something of this sort. He used it to buy BTC and send it to his wallet and the owners of the exchange dailed to stop it. They had to take the whole site down for 3 days and most of us thought we won't be getting anything back but we did. They came back online and allowed everyone access to their accounts.
This gained them trust among some users but I took everything off the platform and never looked back. About a year later they did an exit scam and disappeared with everything, but not with my money.

Oh that's very unfortunate but I believe that if you had hardware problems and had blue screen issue then you should have contacted specialist because there is no way you would be loosing your data because of a hardware issue. Another thing you could have done was to eject your hard disk and just use it on another computer and save that file. But anyways things gone are gone and hindsight is always useless.

For me, I have never faced access issues but I have lost a bad number of bitcoins in exchanges that have turned scam or got hacked like the recent one is cryptopia, I don't know what happened to them.

That is more a investing mistake rather than a technical mistake and yes even when I was new there were a lot of websites which claimed to send double back in 36 or 48 hours but I never fell for these scams because I was new to bitcoin but I was very familiar with online scams and there is no reason why someone will double my money in some hours.

That almost happened with me too when myetherwallet had some issues with certificate and users were being redirected to another website when they clicked the certificate. I almost fell for it but because I saw that something is fishy I decided not to access wallet that day and proved to save my coins, you may read about it here: https://www.theverge.com/2018/4/24/17275982/myetherwallet-hack-bgp-dns-hijacking-stolen-ethereum

I did not but I felt like I did so I know the feeling.

I had a cold wallet once that I knew the password to but did not open it for anything for over 2 years and when I wanted to check if everything is ok with it I struggled to enter the right password. I knew the words it consisted of but forgot which one was first and if there were any numbers in between and in the end. It took me maybe an hour of trying different combinations and nervously sweating to find the right one.

I did lose access to my bitcoins one time and that is because of my stupidity. I forgot where I put my private key, the same with my altcoins since I accidentally deleted the JSON file and just realized that after clearing up my Recycle Bin. Take care of your bitcoins you guys, especially private keys, seeds and files like JSON. IF you have a lot to hold better buy a ledger.

I honestly have not had any issue with the wallet the I am using to store my Bitcoin. There are people who have experienced losing their private keys which yield to such negative scenario. Some are being hacked, and some are being scammed. My opinion to this is to not give private information to anyone just to not be prone to being hacked. That is your money in the first place and you have the only rights to access that. Also avoid logging in into multiple devices using your wallet. If you are into online website wallets, always check the credibility as well as reviews from other people who have experienced engaging into that website just to be sure of not being scammed.

There are also hardware wallets wherein one investor could also store their holdings which provides additional security for your Bitcoin. But be careful of misplacing such hardware wallet because some hardware walleta do cost that much.

Thieves from Yobit blocked my account and simply stopped contacting me. While they promptly respond to others (I asked other people to check). By the way, need to write about this in the scam section when I have time.
A very good lesson for me is that you cannot trust scammers like Yobit.net.

That is a really terrible thing, how much BTC did you lost because of that? This shows it is important to have several backups of our wallets, a simple way to backup your information is to store your keys in a text file and have a copy in an USB that way if your computer breaks you have a backup that will allow you to recover your coins, it is also a good idea to have a paper backup of your seed that way even if your USB fails as well you still have an additional way to recover your coins.