The trade it and leave it rule... why did I not follow it?

I was alerted of this trade via my friend's analysis which I also deemed fit to enter at my own risk. At 2017.07.26, Dax retested the broken support (which was also the 8 EMA at that time) which resulted to a formation of a bearish pin bar.

At the split second that I've adjusted the TP because of 'potential greed,' I have not kept in mind the possibility of such movement when the gap was filled. At the time the gap was filled, Dax, without hesitation, reversed to the upside probably for some breather. Sadly, it hit my SL which were adjusted to my entry levels.