5. Creating limits –
Although you may have certain limits (such as financial, or certain capacities), when you create false limits, you are hindering your intelligence and ability to learn. When you put obstacles in the way, that are not really there, you are never going to try things. This will not only kill your intelligence, it will also stop you from trying new things, and learning new things that can make you better, and can possibly make you a more successful person. So, remove irrelevant limits, and those which are only created by you in your mind.
6. Drinking –
Although it is something enjoyable, alcohol does hinder your intelligence and ability to comprehend or grasp subjects. So, drinking every once in a while will not kill all brain cells, but you should know that alcohol (and drugs), will hinder, and kill your brain cells, making it harder to learn new things. So, if you do consume alcohol, it should be done lightly, and it should be done infrequently, so as to ensure you are not going to cause damage to your brain, and possibly cause problems with the future ability to learn new things and expand on knowledge basis.