what you are trying to do now ( at least according to what you have described) iis also not easy. In the past 6 months, US market rised almost 30%.. This means every month you have to buy 5% higher on the price, sounds scared? yes, probably not even wise if your trading horizon is less than a year. However, if you are talking about 15 years or 20 years investment time frame, This is just part of your game plan. It is the DISCIPLINE. While on the other side, some people also talk about sell high first then buy lower. They are not wrong neither, provided their trading time frame is in week or even days. Everyone has different personality, different belief, different knowledge and background, different time they can spend to watch the market. The importance is to align the strategy consistently into your character and life. Both long term investment and short term speculation can lead to big win or loss. The difficult part in fact is not on the perception, but execution.