"Don't mess with people with thick necks" may have some truth, but it is not absolute. The meaning of this sentence is that if a person has a thick neck, he may have a bad temper or other negative characteristics, so he should not be provoked.

First of all, people with thick necks may have certain physical problems, such as thyroid problems or obesity. These physical problems may cause them to feel unwell or emotionally unstable. Therefore, conflict with these people can make things more complicated.

Secondly, people with thick necks may also have certain negative characteristics, such as violent tendencies, emotional instability, or selfishness. Conflicts with these people may put you in dangerous situations, so it may be wise to avoid conflicts with them.

However, not all people with thick necks have the above problems. This is just a general statement and cannot be generalized. Everyone has different personality and behavioral characteristics, so we should judge whether they have certain problems by observing and understanding their behavior. At the same time, when encountering conflicts, we should also handle the problem with a rational and calm attitude, rather than treating specific groups of people with prejudice and discrimination.