There are those who don't believe on superstitions and when there is a happening, they will only think that is due to their actions. They say that positivity attracts luck. The explanation would be is because when you are positive, you are also confident about your actions i.e. you did a proper research about the team or player that you will bet in, if we are talking about gambling.
I am one of the many people who believe that when you think positively and are surrounded by people with a positive aura, the result is that your luck level will be better. I don't know if this is superstition or what, but that's what I feel, when I play when I'm happy, whether because I get a bonus from work or my friends are around me, I often win. I don't know whether it's just a coincidence or not, but from this I'm sure that luck can happen because of the positive aura from ourselves and the people around us.
I think that when a player is not bothered he wouldn't have much disputes or troubles while gambling. His results will be acceptable and reasonable to him. Because within himself he's better off with those results win or loss. Due to his happy mood and type of surrounding filled with people who posses positive energy. Hence, gamblers are meant to realize the need for being in a good mood while gambling. In relation to what Op just said about his friend, it's fine to assume that his presence lifted his friends curiosity and made him have a balanced thought on his decisions. Yet that doesn't contribute to the maths behind how people win gambling.
Players only add such thoughts to back themselves with some feeling that gambling results could be manipulated. A player gets to win unexpectedly, and will tag it luck. But, I would say the casino have the best answer to all the questions regarding what strategy is best needed to win in gambling. It's not for the players to conclude. If they were any proven track record of OP being the reason people win big in gambling, he would have been spending all his time with gamblers. His friend won unexpectedly in Op's arrival to his house. So if what they think of such believe is true they can recreate it multiple times and make a kill. Aside winning money, gamblers enjoy a better gambling experience when they gamble with their mind at rest.