If you thought that human intelligence has its own "limit" from birth, then you should discard this stereotype: you can work on your mental development at any age.
The functioning of the brain depends on a huge number of factors, so you should not look for an “excuse” in genetic predisposition.
There is a close relationship between intellectual work and coffee: the drink has a very qualitative effect on our mind.
So, a few cups of coffee throughout the day will help you engage your brain more widely.
If you have intellectually developed people in your social circle, you yourself will eventually begin to reach their level. Therefore, for friendship and communication, it is worth choosing people you want to be like.
Experts classify books, crosswords, scanwords, sudoku, watching scientific programs, reading articles and other developmental activities as such "trainers".
Such hobbies need to be practiced on a daily basis.
Not everyone knows that doing sports helps the brain work more actively and efficiently. Therefore, moderate physical activity is incredibly important.
In order for the brain to actively learn, you need to practice its skills. Start thinking, engage in discussions, keep a diary.
This will help you systematize your knowledge in a particular area, and will also help you use your intellectual skills to the fullest.