A mental block is often a challenging thought.
Indicator #1: An emotional reaction of denial, frustration, or anger
Is there someone you just don't particularly like, or an environment that leaves you in a bad mood and you wonder why? This may be an emotional reaction to a feeling of envy or competition relating to that person or that environment. Once you notice it there is an opportunity to grow.
Ask yourself: What is the trigger?
Then redefine the situation with your new knowledge.
Indicator #2: You consider yourself above or below others
Do you catch yourself being dismissive of your own knowledge and opinions or talking down to others assuming they don't understand something? It can be subtle and hard to catch yourself in the moment. The one-up or one-down doesn't need to be extreme to be a signal.
Ask yourself: What makes you better or worse than the other person?
This act is humbling and opens the ears to active listening - which can repair the conversation.
Indicator #3: Setting unattainable goals
Do you set lofty goals and rarely attain them then feel frustrated and down because of the failure? Having unrealistic expectations for yourself and others is a recipe for discontent. Objective reality is the greatest teacher.
Ask yourself: How realistic is this goal based on my self-knowledge?
Use an analysis like SWOT to determine how likely you are to succeed.
Strengths
Weaknesses
Opportunities
Threats