Many good points that I also preach endlessly. Learn to read price, not oscillators or derivations of price. Good job. As for this chart - It would be extremely helpful if you put this chart in log form since the 1987 crash looks like a hiccup.
Yup I posted the Log version of the Dow Jones for the last 100 years using 6 month Candle bars. Highlighted 1987's crash that occurred in the midst of one the the secular bull market cycles after Jimmy Carter's era during Regan time. Its in one giant uptrend in this time frame for the last 100 years and the sentiment is oh so right for it to just keep on ripping. Buffet was right never bet against USA lol this is the megatrend of the ages right here!
Sometimes the market can stay overbought or oversold for quite a long time, specially when you look at THE big picture like this. I think many countertrend traders fall into this trap and rip their profits. At last, it's always the game between the buyers and the sellers, their positions, their profit taking. No one knows and no one should care a lot about where the mkt is going, that isn't needed for making money, but you you react to the signs that the mkt is giving you. I have been here for a short time, but that's one of the best charts I've seen, well done.