I think people who are looking at long term wealth building are better off looking at John Bogle's work. The key is this, you absolutely must stick to investing in the index as a whole, but the issue there is fees you pay is a percentage of your investment, even if small, over years compounds against you. That might look small, but its a double digit percentage if done over decades. Hence picking a fund that charges you the lowest is the key.

Buffet does this better. He basically takes the float from insurance business(Geico) and invests in the index his company manages. This basically sets you up for a long compounding cycle. Translation- You are basically investing in the US economy.

Apart from this there are some base businesses in an economy that's under long term multi year climb. Now anybody who is staring at stock charts(weekly) will tell you eventually you do learn to 'Pyramid upwards' on stocks that are clear winners. Lots of literature has been written on this.

All said and done, you can be rest assured there only at best 10 such stocks in any economy. Once you find them, you do periodic audit if the companies are holding up good and just keep putting in money as time passes.

I don't remember where- but I remember reading, Fidelity found out the most profitable accounts belonged to people who were dead. That says two things. 1) You have to hold stocks for long periods of time, like really long periods of time(Index, and some of its constituents that are carrying most of the freight) . Most people won't make it. 2) Live long enough.

Quite literally once you gain the skills to pick stock. Next single biggest skill you can master is to be healthy and live long. These things take lots of time to work.