I first heard about Bitcoin in mid-2010 when a man by the name of Laszlo Hanyecz convinced someone to accept 10,000 bitcoins (worth $42 million USD today) in exchange for two Domino's pizzas. It bounced back up on my radar again in 2010 when someone exploited a buffer overflow bug (CVE-2010-5139) to create 184 billion bitcoins from thin air. A new release of the client was published within five hours of the discovery, and contained a soft fork change to the consensus rules that rejected output value overflow transactions (as well as any transaction that paid more than 21 million bitcoins in an output for any reason).
It was in the fall of 2010 that I made my first attempt at bitcoin mining. I had built a new desktop PC in 2009 and had splurged on a top of the line video card (the Radeon 5850). GPU mining clients for bitcoin were becoming popular on the bitcointalk.org forums and many people were successfully mining using CUDA (Compute Unified Device Architecture) for nVidia graphics cards and OpenCL for ATI graphics cards. CUDA and OpenCL are parallel computing libraries that leverage the inherent parallelization capabilities of GPU's. The tools were very crude back then though and I was unable to successfully get them working with my GPU.
It wasn't until June 15th/16th, 2011 that I bought my first 19 bitcoins for 391.59 USD (20.61 USD per BTC) on bitmarket.eu. Bitmarket.eu was a bit of an escrow service that connected "trusted" buyers and sellers together. I verified myself using my eBay identity, as I had a large number of positive reviews. Once a buyer and seller were connected and a price was agreed upon, the seller would send bitmarket.eu the bitcoins which would be held in escrow until payment was sent by the buyer and verified by bitmarket.eu. The most common method of payment was PayPal, however there were risks associated with using them to pay for bitcoins. At that time PayPal did not allow it's service to be used to buy or sell digital currency (bitcoin, as well as MMO currencies such as EVE Online ISK, Everquest ZAM, Bitcoins, etc). This meant that buyers and sellers could not rely on PayPal to act as a mediator in cases where a dispute arose. Despite the high barrier to entry, I had purchased my first bitcoins!
It was at this time that my interest in bitcoin began to wane. 4 days after my purchase, someone used hacked credentials to steal $8.75 million USD from the Mt. Gox bitcoin exchange, causing the price of bitcoin to crash temporarily on June 19th, 2011 (Mt. Gox would go on to lose almost half a billion dollars in subsequent hacks/thefts/frauds, read more here). I was busy planning my wedding that summer, and got married in August of 2011. I forgot about my bitcoins, and didn't give them much thought until I received an email from bitmarket.eu in February 2013. They had been hacked, and my bitcoins were gone.
This is the part where you ask why someone so familiar with bitcoin would not store his coins in an offline wallet. I was well aware of the risks, having read the bitocintalk.org forum thread started by Allinvain in June of 2011, detailing his loss of 25,000 bitcoins to a hacker who compromised his bitcoin wallet. Even back then it was a huge sum; $500,000 USD in 2011, $105 million USD today. The simple answer is that I had forgotten I even owned bitcoin, and at the time I had purchased, bitcoins value had dropped to next to nothing. I didn't expect bitcoin to really take off the way it did and didn't make any effort to secure my coins.
It wasn't until earlier this year that I've become interested in bitcoin again, and while I do wish I still had 19 bitcoins laying around, I'm glad I had some fun along the way and learned a valuable lesson. I'm planning on developing my alt-coin for fun, and may try my hand at building an Ethereum contract or two.