I know that being positive will keep negative energy ways

A dropped match on wet grass does nothing at all. The same match in a bin of paper takes the building. The match was never the interesting variable.

Most negativity that lands on a person needs material to catch on — a bad opinion of yourself it can confirm, an old grievance still dry enough to burn. Someone in reasonable shape absorbs an unfair remark on a Tuesday and has genuinely forgotten it by Thursday, not through strength but through lack of tinder.

That's a slower kind of protection than a shield and considerably more reliable. It has little to do with deflecting anything. It's about what happens to be lying around inside when something arrives.