Actually common problems in not accessing the wallet is
forget the Private keys which is very important because we can't access again our wallet. That's why always careful in storing this keys.  

And in my experience when I was a newbie i lost access to my wallet that contains 0.2 BTC before and price of this before are only 50 USD. Which is not hurt me but when price Increase this give me frustrations to open again because i can't still find private keys.  I accidentally deleted this in my social media messages drop.

So far I personally have never lost access to any wallet that I used after a past event about losing access to an exchange, at least after that incident I have always been more thorough in terms of storing all security data. Yes, I have never lost access to my wallet since I was in this market, but I have lost access to an exchange in the past, and the only regret is that I kept at least a few altcoins on the exchange until I finally tried to be patient because I lost all crypto I have there, while basically these altcoins have the potential for the long term, even now I still see very good growth.

Ive tried it once but luckily it is just a small amounts of coins stored on an online wallet and ran away all of the funds.
Retreiving it back? Theres no way on doing that once you have lost then its lost forever. This is why its important that
we should store out coins and keep its PK away from other people.As said, not your keys then not your coins.

Ive lost once when im still newbie but it did never happen once again.

I got hacked because I installed an unknown wallet whose owner was trustworthy but turned out to be a scammer. Lost $150 in the hack in 2017. I also lost access to my coinbase wallet as for some unknown reason I couldn't login with 2FA but since the wallet was empty, I did not bother but coinbase is not trustworthy as such 3rd-party wallets act as if your money is theirs and freeze your account. 1xapo did the same after which I had to verify myself and access my account.

I haven't lost access to bitcoins like that but I remember when I was new to bitcoins I was first introduced to blockchain.info and I made a new wallet there with some temporary email because I didn't knew giving my mail email id was safe and worth it. Then after a few days when I tried to login, it said that an email has been sent to your email since you are logging in from new browser and since I used a temporary email I actually could never open my wallet again but I don't know if I had any bitcoins left over because I did some work as a freelancer and got paid in bitcoins which I believe I sold right away after keeping in blockchain wallet for little while.

I still wonder if some BTC are there but not quite sure and absolutely no way to retrieve them.

Yes, I have lost access to my Bitcoin few times before. When I wasn't that much experienced in bitcoin trading, I used to trade in sites that were not trusted and also not very secure. I’ve lost millions of my Raiblocks MRI token (XRB) on BitGrail exchange. From then, I always try to search the ratings and feedbacks of the site and then trade my coins.

No, actually I am still using the same wallet I use the first time I have my first bitcoin.
It is a mobile wallet exclusive only in my country and what I do to protect it is, I never expose it to anyone and remain as my main wallet where I store and save enough bitcoins for the future bull run.

True and false at the same time. Having complete control over your private keys does not mean that you will not lose that control at any time, what has happened to many and is still happening today, and there is no doubt that it will continue in the future.

Personally, I'm not surprised at those who lost their private keys at a time when BTC could be mined with a regular computer, or you could buy 500 BTC for a few bucks, or get 5 BTC on a single claim on faucets. They can say, "easy come, easy go" given that they have invested very little value in order to get into Bitcoin, but they may be sorry that they did not recognize the potential behind the technology, because in that case they would have completely different treatment of their private keys, wallet files and passwords.

I never lost access to my coins, and I always try to improve my chances that this never happens, and to point out to others that they must pay close attention to the way they treat their investment.

Gladly I never encounter losing access to my bitcoin wallet. As much as possible I have a back up all of my private keys in case I lost it. If we ever think of our btc that we have and a sudden lost we cannot retrieve it once your phrase or keys lost. It's very important to have our assets to be kept all the time.

This is probably one of the most unforgettable experiences I had ever since I started engaging with cryptocurrencies. I had just merely started exploring how things work in this forum and I have realized that coin storage is one of the things that I must think of having before starting to send out applications for signature campaigns and such. Due to the research that I have been making that time, I was bombarded with so much information, it slipped into my mind to save private keys and some authentication data especially for wallet recovery. I'm lucky enough to experience it earlier before I even started putting coins into my wallet. From then on, I became very vigilant in the information I am putting in each of my account, wallet or in any online profile, and to not forget saving these data in safe place.