Oh yeah. I have lost a lot. I am not sure how much but when I first got into Bitcoin, I was sending back and forth between a couple of my own wallets to learn how it works and I lost like $10 worth which is like .1 BTC or something. I have also lost some by locking myself out of paper wallets using the BIP 38 encryption.

I have learned all of my lessons and now I know that the best way is to keep things simple and have lots of backups. Experiment with small amounts and don't do anything stupid like messing with lots of complexity.

Keep it simple until you have a larger stack and really know what you're doing.