The phrase "no one cared who I was until I put on the mask" is a reference to the idea that people may only pay attention to or take notice of someone when they are hiding behind a disguise or facade. It suggests that the individual was not valued or respected in their true identity, but once they put on the mask, they gained attention and recognition.
This phrase is commonly associated with the character of Batman, who wears a mask and costume to conceal his true identity as Bruce Wayne. The phrase is often used to express the idea that people may not recognize or appreciate someone's true worth until they present themselves in a different way.
It can also be interpreted in a broader sense as a metaphor for people who feel invisible or unimportant in their everyday lives, but when they put on a certain persona or mask, they gain attention and respect.
It's worth noting that the phrase may also have a negative connotation, suggesting that the person may be hiding behind a mask to gain attention and recognition, instead of being true to themselves.