They make you really believe that is more like a skill and if you are good at it, it works.
My friend told me that is just about how lucky you are, and not a skill.
So, should I stick with holding or playing day trade is a better option?
I think that both things are needed. You can have really great luck and no skills in trading and earn much more than even the most experienced tough trader.
Both indeed, luck is the product of constant trying, but skills to know what you are trying and how you do it is also needed. Combination of many factors affect day trading results, sometimes you will have more luck then you expected, sometimes with only your experience can help you to avoid some bad trades.
More experience trader you are, more factors you include in your calculations, more chances to be make a good trade you have. Less experienced traders include less factors and with them luck is one of the main things they count. Day trading is like skill based gambling, I see it like that, if you are not ready for ups and downs don't even try to practice it.