Covering your head with hijab or scarf is required in alot of religions then why everyone points to Islam?

It says in Bible that females should cover their heads, Mary used to cover her head with a veil. Most Hindu women cover their heads, Jews women cover their heads. The reason can be cultural, religous, or your personal prefernece. But whnever I tell people I'm Muslim why do they always ask me why I don't wear. Hijab, is their any strong base that I can tell them as to why I just don't cover my head?