Whenever we think about success in investments, the immediate association or measure is mostly often the financial gains, how much money has been made from the investment, the ROI or even the size of the portfolio, but we often forget to look at a more nuanced perspective of measuring an investor's success, a quality that is extended far beyond mere monetary outcomes, which happens to be the wealth of knowledge and breadth of experience which the investor has achieved throughout their journey.
Take your wealth of knowledge and give me the money (ROI) 
. Every investment targets to generate profits and when the profits and not knowledge. Weather the investment generated profit or loss, the investor will always gain knowledge from the invest in the way of identifying areas of improvement to make more profits and cut down cost. You don't only learn from failures as most people make it look, especially the motivational speakers, learning can come from being successful in business and also from failure.