The phrase "a person not himself" typically refers to someone who is behaving or acting in a manner that is out of character for them. It suggests that the person is not displaying their usual personality traits, emotions, or behavior.
There can be various reasons why a person might not be themselves, including:
External factors: External circumstances, such as stress, trauma, or significant life events, can affect a person's mood and behavior, leading them to act differently than they usually would.
Emotional distress: Emotional struggles, such as anxiety, depression, or grief, can cause a person to behave in ways that are not in line with their typical demeanor.
Health issues: Certain physical or mental health conditions can influence a person's behavior and personality, leading to changes that are not characteristic of their usual self.
Substance use: The use of drugs or alcohol can alter a person's behavior and decision-making, leading them to act in ways that they might not when sober.
Temporary circumstances: Sometimes, people may act out of character due to specific situational factors or pressure from others, but they return to their usual selves once those circumstances change.
It's important to remember that human behavior is complex and influenced by a multitude of factors. When we encounter someone who is not acting like themselves, it's essential to approach the situation with empathy, understanding, and support. If a person's behavior seems concerning or persistent, it may be appropriate to encourage them to seek help from a mental health professional or a healthcare provider.