What's the worst mistake you did with your Bitcoin? It can vary from starting to use Bitcoin to buying dumped Altcoin to gambling.
The worst mistake I made with Bitcoin is... Buying cloud mining hashrate. I bought 0.02 GH/s CEX.IO hash rate voucher at SEOClerk for $2 USD - or maybe $1 USD. I thought with 0.02 GH/s, I would be making a profit in half a year.. And I was wrong.
Well, I bought using the free five dollars coupon. So that does not count as making a mistake with Bitcoin. However, the slow profit lead me to buying hashing power from CEX.IO and later on.. ZeusHash using the Bitcoin I earned from signature campaign.. Again, I thought I would be making profit in a few months. Till today, I'm sure I have not make any profit from both the company yet. CEX.IO stopped their cloud mining operation and.. ZeusHash.. What do you think.?
Edited (15 May 2016):
First edit since this thread was posted. Anyway, after reaching more than 100 pages (103 to be exact), today I will list down some common ones.
1. Gambling
2. Not knowing Bitcoin earlier.
3. Participating in HYIP & Wrong trading technique (both Altcoin and day trading).
4. Sending to wrong address & lost of wallet.
5. Cloud mining & scammed trade.
My worst mistake with bitcoin is trust hyip program. Last month there hyip named cryptoprime. I give a deposit large enough there, because I see the web it has been running long enough and it looks legit.
For the first deposit smoothly without any problems, but for the second deposit was never entered in the accounts, they reasoned there blockchains problem. And BUMP 5 days later there website is mising from network. haha
My advice do not ever believe hyip program.