Have you ever felt so excited, or angry, or scared, that you couldn’t recognize yourself? Have you ever been so emotional that you behaved like a different person? To be beside oneself is to act in a way that is not normal for you. It’s used with all kinds of emotions, from feeling anxious to feeling sad.
A mother might be beside herself with worry if her young son doesn’t come home when she’s asked him to return. A high school student might be beside himself with excitement as he waits to hear from universities and colleges. A little girl could be beside herself with sorrow when her pet dog dies. A tech savvy might find the activity of visit website is no longer fun and exciting.
Being beside oneself means having strong feelings about something.