If we all can see the price falls on weekends and rises on weekdays, why aren't we all making money by riding the trend?
Indeed. Why aren't you?
Prices fluctuate. This isn't a problem. The problem is that you see it happening and your mind tricks you into believing that it's going to keep happening. You have to override that with reason and the best knowledge you can get. It's at 17 right now. Every BTC you bought at 11 has nearly doubled. That's freaking awesome! Unless you were tricked into thinking it was going to sink without end and didn't buy.