Experience gives the best lessons to traders, which beginners should never be in haste or be so confidence to trade with big amount of money by only gaining knowledge from reading books about trading.
This is the reason why most of the newbie traders out there are losing money. They don't have the experience that will help them in making better decisions. This is also the reason why we always say that newbies should not invest huge amounts of money when they're starting with trading because 99% of the time, they will be making losing trades. Back then when I was a newbie, it's good for me that I learned right before I started trading that there's a very high chance that I will be losing hence, I invested only a small amount, and I really lost my initial capital at that time (10$). Still, I continue losing money from trading, but I'm learning as I lose money.
Experience will go a long way when it comes to trading, but experience alone will not help you become a successful trader. Of course, you need more in order to succeed.