1/ OK Twitterverse. Here's my most costly investing mistake and what I learned from it. Back in Aug. 2007, I bought my very first shares in $NFLX for a split adjusted cost of $2.44. I didn't have much to invest at the time, so I put down my entire $250 that month on $NFLX shares.

2/ Mind you, being so new and wet behind the ears, I didn't yet know what type of investor I was. I heard people that "sounded" much starter than I was say, "Take your money off the table, and play with the houses money." Note the comparison to gambling (I did NOT at the time).

3/ Fast forward to March, 2009, I sold about 10 shares of $NFLX and patted myself on the back for achieving a 138% gain on those shares. I kept the remaining 4+ shares, because, I had recouped my original investment and was playing with "house money."

4/ Fast forward to today. Those 10 shares of $NFLX were the subject of a 7:1 stock split in July, 2015, so actually, its 70 shares we're dealing with not 10. I sold those shares for a split adjusted price of $5.95. Today, $NFLX shares are trading for ~ $489, up 81x in price.

5/ I made an impressive $242 gains on a $175 investment. However, by selling WAY TOO SOON, I gave up $33, 800 -- and counting. It was only later that I realized that in investing, there is no "house" -- it's all my money.

6/ Fortunately, I have learned from my early investing faux pas. So while it was costly, it was important to my continuing education as an investor. Since then I have been (and continue to be) the proud owner of numerous multi-bagger #stocks that I did NOT sell too soon.

7/ Here are a few:

$MELI -- up 2,757% and counting
$TSLA -- up 2,150% and counting
$SHOP -- up 1,909% and counting

Oh, and the remaining shares of $NFLX and those I added later at a higher price? up 3,236% and counting.

8/ The moral of this story:

Multi-baggers come along every day. Finding them is only half the battle. The other half is controlling your emotions through the daily, weekly, monthly, and yearly gyrations that come with every investment. As long as the thesis holds, so do I.

9/ That, my friends, is one of the secrets to successful investing.