3.5 years ago, I used to day trade gold futures. Over the course of ~20 trading days, I doubled my initial investment. But every single day, I was on my phone during classes looking at live streams from COMEX for the current month gold futures contracts. The only break I got was the one hour a day that the futures markets would be closed, during which I pretty much did all of my hw, ate dinner, and watched TV. I tried to close out most of my investments before going to bed, but sometimes that didnt happen, either way, I barely got 5 hours of sleep/day during that month.
I made a lot of money, but it really affects the lack of sleep really affects your critical thinking abilities and reasoning. You end up making trades that you wouldn't have otherwise, and behave in weird ways because of the stress. I felt like I was missing a piece of me when I wasn't in front of my computer watching the markets, or on my phone trading (I used to execute 10+ trades on some of the more volatile days).
So I closed up shop, and cashed out and didn't trade after that. If I had, I probably would have made millions by now, but I would have probably flunked out of college doing so, and not gotten any sleep.
I invested in TSLA ~3 months ago after putting down my reservation in January. I only put in the money I could afford to lose ($1500) and invested it in a split between short term (Jun) and long term (Jan '14) options. As the bull run began, I kept on rolling up my strikes, and moving around the months etc. and now have made 10x on my initial investment (or to put it another way 14% of my car is payed for). All of the 10%+ days have been a lot of fun but I keep on checking the prices too much for my own good. I barely did any studying this semester (but its okay, I'm graduating next week and already have a job so not a big deal). But for now, I think I'll just sit tight on the cash until the stock returns to earth or I finish building my trading algorithm.
