Right. So, you were taking a risk trying to buy in the dips and sell in the bumps, you were not following your own advice to "Always check if something changed about the company itself." Which is fine, it worked out for you.
Of course, the bigger picture challenge is that -- modulo market freakouts -- everyone else is also "checking if something changed about the company itself", and that's already built into the market price, that's kind of the model of how the market works. To make money by buying in dips only after checking if something is changed in the company itself, you have to think you are better at noticing or predicting changes in the company itself than everyone else, I guess?
Here's the thing, though: I think most of the time it is market freakout. Even if something did change about the company, quite often the market will freak out about it in one direction or another. I really think Warren Buffett is one of the few investors who really pays attention to the actual value of companies. Most investors just sail on hype.
Of course, the bigger picture challenge is that -- modulo market freakouts -- everyone else is also "checking if something changed about the company itself", and that's already built into the market price, that's kind of the model of how the market works. To make money by buying in dips only after checking if something is changed in the company itself, you have to think you are better at noticing or predicting changes in the company itself than everyone else, I guess?