There will always be times when you misspeak, lack focus, or misremember. They can all stem from an inherent psychological phenomenon of the brain.
You may have heard that humans only use 10% of their brain, but this is actually a myth. Most of our brain is always active, even while we sleep. Yet it still frequently deceives us with the following psychological phenomena:
1. The Barnum Effect

The first psychological phenomenon is called the Barnum Effect, also known as the Forer Effect. This is why people believe in horoscopes, online personality tests, or fortune cookies. People believe in vague personality descriptions or general messages that could apply to most people, but because we are part of that majority, we think it's a specific description tailored just for us.
2. Illusion of Transparency

When we experience strong emotions like excitement, anxiety, we may think others can see it clearly too. The difference between our perception and what others actually perceive is called the illusion of transparency. This illusion can make many people feel anxious when speaking in public, thinking everyone can see their tension, but in reality, it might not be the case.
3. Slip of the Tongue Phenomenon

Have you ever intended to say something but ended up saying something completely different? This often happens while speaking but can also occur while writing. This is called the Freudian slip or parapraxis, referring to verbal slips or mistakes.
According to the famous neurologist and founder of psychoanalysis Sigmund Freud, areas of the unconscious mind sometimes shift into conscious behaviors, causing you to say things you didn't necessarily intend in the prior thought.
For example, a child may mistakenly call a teacher dad or a woman might want to tell her friend that she loves Daniel, but instead of saying Daniel, she might mistakenly say the name of her ex-boyfriend. Because of this deceptive phenomenon, the friend might then assume she still loves her ex-boyfriend even though it was just a slip of the tongue.
4. Pre-existing Choice Bias

Bias of Available Choices (Availability Heuristic) is a phenomenon where the brain seeks to create the shortest path to analyze a topic by providing the most readily available examples. For instance, after watching several news reports about car thefts, you might conclude that car thefts are very common and serious in your area than they actually are.
5. False Memory

Our memories are fragile and more susceptible than we think. They are not accurate recordings of what happened in the past. What we remember can change depending on how and when we recall them. False memories occur frequently. They seem real to you but are created by your mind. For example, you believe you turned on the dishwasher before leaving home, but when you return, you find it off. You may think the machine is malfunctioning or someone broke into your house, but in reality, you just remembered it incorrectly.
6. Mockingbird Process Theory

Most of us don't want to think or recall our unfortunate experiences or embarrassing moments. However, the more you try to suppress those memories, the more they pop up in your head. The more you want to forget something and 'tell' your brain not to think about it, the more you will think about it.
7. Surplus Attention
Do you often feel it's hard to concentrate? Sometimes, it's simply falling into the trap of 'surplus attention' phenomenon. Essentially, this happens when our attention dwindles throughout the day after continuously shifting from one task to another without actually completing any of them. Subsequently, it becomes challenging to fully focus on anything. To cope with this phenomenon, try to establish a schedule and allocate time for your tasks.
Source: Bright Side
