Riddle

It is everything to someone, and nothing to everyone else. What is it?

Choose an answer

A.A memory
B.A dream
C.An opinion
D.A mind
Hint: It's a 2-word phrase with 5 letters, starting with "A".

Answer

A mind

Why this is the answer

A person's own mind or inner world is the whole of their experience, yet completely inaccessible and meaningless to anyone else.

This riddle is filed under "What Am I?" Riddles and rated Medium.