Just as rust, which arose from the iron itself, wears out the iron, likewise, performing an action without examination would destroy us by projecting us into a negative state of existence.
So the first step in seeking happiness is learning. We first have to learn how negative emotions and behaviors are harmful to us and how positive emotions are helpful.
Our thoughts really do create our lives. They've done a lot of research showing if you're an optimistic, positive person you will be a healthier person than if you're a sad, depressed, negative person.
There is one thing of which I can assure you. If good performance of the fund is even a minor objective, any portfolio encompassing one hundred stocks (whether the manager is handling one thousand dollars or one billion dollars) is not being operated logically. The addition of the one hundredth stock simply can't reduce the potential variance in portfolio performance sufficiently to compensate for the negative effect its inclusion has on the overall portfolio expectation.