It's worthwhile to note that there isn't usually one single investment strategy to use throughout your life.
At different stages of life, you are in a different phase with regards to wealth management. Before your 40s, it's important to focus on capital accumulation. From 40 onwards, it might be important to focus more on capital protection.
When you are in your 20s and 30s, the amount of capital you have for investing is usually limited as you might not have reached your peak earning years. For those in the 20s, accumulating $100,000 by the age of 30 might seem like a tall order if your monthly salary is $4000. When you are in your 40s, the same amount of $100,000 can usually be easily accumulated either through savings or returns on investment in 1-2 years, especially if your portfolio has already reached a sizable amount of $1M.
Hence, it's very important to understand that investing before 40 is very different from investing after 40....