Question

when can one hold his head high?

Answer 1

Also, hold one's head up; hold up one's head. Behave proudly; maintain one's dignity. For example, After the bankruptcy Mr. Jones still held his head high, or Grandma told Brian he could hold his head up because he'd tried extremely hard, or After that newspaper article, I'm not sure I'll ever hold up my head again. All these expressions allude to a posture of pride

I hope it's help you

Answer 2

When one is proud, happy, not afraid of the fault they did and is a good human.