Perception Is a Reflection
"Our perception of us is often a reflection of others' perception of us."
That's why we often do well when others (that we look up to) show confidence and belief in us, and fall short when significant others see us as lacking in something.
While this is true for life in general, it resonates equally at the workplace. So often, the same person thrives working in one company or working with a specific manager, but comes up short in a different setting.