2 Most Common Bad Habits Limiting Your Growth
I have already highlighted one factor, which can kill your progress, especially if you are a rational thinker. That factor is a cognitive bias, which you develop through time and, in most cases, never notice until you start questioning yourself or get direct feedback, pointing to scientism.

There are, unfortunately, many more tiny cognitive biases which crawl slowly into your subconscious and get rooted there. They create limiting beliefs and trigger your procrastination. 

I want to highlight two most common bad habits, which are based on a negative self-talk. The good part is that - as soon as you notice those habits, you can start changing them.

Fixed Mindset 

Fixed mindset is a belief that your potential is predefined and limited, and that you have an inherent traits that do not allow you to learn or achieve something.

Here is what Carol Dweck writes in her book on the topic

Believing that your qualities are carved in stone creates an urgency to prove yourself over and over. If you have only a certain amount of intelligence, a certain personality, and a certain moral character, well then you’d better prove that you have a healthy dose of them. It simply wouldn’t do to look or feel deficient in these most basic characteristics.

Have you ever told yourself "I am just bad at Math"? This is your fixed mindset in action.

This type of self-talk destroys your confidence, fuels your imposter syndrome, eliminates your grit and discipline. It lowers your expectations in regards to yourself. Low expectations rarely yield growth and often lead to frustration.

You may occasionally encounter someone who can’t develop using the existing practices and methodologies. It does not mean that they won't be able to change the situation at all. The real barrier is most often the belief that the person won’t make progress. 

Quick Conclusions

Another bad habit is jumping to conclusions and making generalizations based on insignificant number of events. Have you ever failed or made a mistake and thought "It seems this approach will never work for me!"?  

Quick conclusions are made of different biases and cognitive distortions. Rationality and bayesian thinking are tools people apply to get rid of those biases and distortions.

If you really want to make the conclusion about a methodology or some of your abilities, make more experiments to gather more experience in various contexts. Talk to people to learn from their mistakes. Talk to experts to get their professional perspectives on the issue.

There are always several strategies for getting similar results. The behavior of any system in real world is too complex to be easily predicted. There are a ton of factors influencing the outcome of events. If you have not seen enough examples in diverse contexts, you can't make definite conclusions.

How to overcome this habits?

  • Acknowledge your imperfections.
    Do not hide from your weak points. You won't be able to improve something if you do not know the real state of things. Treat you weaknesses as an initial state of the system and figure out how you can improve it in small steps.
  • Reframe fails and mistakes as experience you can learn from.
    Everyone make mistakes. The difference between great and mediocre specialists is that great specialists learn how to not make the same mistakes again. They make
    more advanced mistakes instead.
  • Stop seeking approval.
    Do you really care about your image more than about your progress? Do you want someone else define goals for you? It's very dangerous to allow other people define your worth.
  • Celebrate your progress and growth.
    It is very important to feel positive emotions when you make meaningful steps forward. It does not really matter how big is your achievement. What matters is your progress.
  • Emphasise growth over speed.
    Once again, it's not the magnitude of your achievements or the speed of your growth.
    What matters at the end of the day is that you can do more and achieve more than you used to do before. Every step forward makes you better than you used to be.

To dive deeper in the topic, I would recommend researching and taking actions from these books: Learned Optimism, The Mindset: The New Psychology of Success, Feeling Good: The New Mood Therapy.