It’s common to say that “hindsight is 20/20”.

But can hindsight teach us anything about the future?

Just as athletes should review game film, so should other professionals review past performance.

While we should not be discouraged by past mistakes, we should not completely ignore them either.

Furthermore, past mistakes don’t have to be ours, they might belong to others too.

In the spirit of learning from mistakes, here are some mistakes that are generally useful to avoid.

Investing with clouded judgement

There were many dot-com era companies not more than 25 years ago which either folded or never recovered from their all-time valuations, much to the dismay of investors.

When evaluating a company, whether it’s GameStop today, Tesla tomorrow, or an AI company of the future, we should be extremely cautious about paying unjustifiably high prices for lackluster value.

If you can’t explain a bull or bear thesis with great depth, you really are just guessing, which is a bad basis for any investment. Whether you are an employee or an investor, you should always evaluate the collective intelligence and bull thesis for any company’s founders and its key executives, to see if they make any sense.

Not moving quickly enough

In a rapidly changing world, changes can happen seemingly overnight, and nobody can stop it.

Trends such as cloud computing and mobile computing have carved out new winners and losers, turning some of America’s once “invincible” juggernauts like Intel and IBM into tech laggards. The lesson here is - initial success is good, but the ability to re-invent oneself matters more.

Even if a company appears to be doing great today, the lack of a fast-adapting leadership can cause it to be catastrophically late to the party or miss the train completely. Speed and reinvention can make or break tech companies - Microsoft, Amazon, and Apple have taught us how it’s possible to correct course or capture new markets.

On an individual level, we should prefer to develop ourselves rather than waiting for opportunities to come. Metaphorically, if asteroids hit the Earth, we might survive as fast, flexible mammals, but not as slow, stubborn dinosaurs.

Not changing our minds

It’s easy to blindly trust ourselves (“my intuition is always correct”), and it’s easy to surrender to authority (“she sounds smart, so we’ll just do what she said”).

In reality, regardless of how we view our own abilities, we should unconditionally try our best to seek the truth and continuously refine our mental models.

We should seek to brutally test our beliefs over and over again, and be willing to throw away incorrect models. When we disagree with others, instead of avoiding confrontation or being too scared of backlash, we should proactively question and explore clashes of thought, and seek to resolve apparent contradictions through evidence and logic.

If we let our ego get in the way of the truth, it becomes a disservice to our peers, ourselves, and the work that we do. The more we put aside our ego in favor of the truth, the better off the world becomes.