WHAT ARE WELL-KNOWN INVESTING MISTAKES?

It's a fact that "the most important thing is likely to be what is not changing and what will likely never change", and that happens to be, unfortunately, well-known investing mistakes, some of which are enumerated below - with the hope that young investors would eliminate them in the early years of their investment journey itself:-
1. No financial goals and asset allocation strategy.
2. Over-weighting in high-risk, short-term, non-diversified products.
3. Asset duplication in portfolio due to inadequate knowledge.
4. Ignoring inflation and taxation when setting goals.
5. Not choosing suitable options for specific goals as per risk profile.
6. Not prioritizing and reviewing financial goals for allocating resources.
7. Using one strategy for all investments and expecting unrealistic returns.
8. Basing investment decisions on emotions, "uncle's" advice and complexity.
9. Maintaining an extreme view of conservatism or aggressiveness.
10. Greedily timing the market and refusing course correction.