Making new magic is a bit scary. The Fidelis charm for "secret keeping’ is meant for places, not people or things. She had already experimented with things, people were much different, though, and with magic anything is possible. In theory, self-obliviation is possible, but in practice, one does not want to end up like Gilderoy Lockheart. She started with something small. She made the sobriquet "Brightest Witch of Her Age’ a secret. It was a delight to read the  Prophet without that particular phrase. Then in her next interview, her last, where she shared her thoughts on the Ministry’s failure to act, she watched the reporter struggle with what to call her. When she wrote the phrase out for the intrepid interviewer, it was like watching the light dawn. The next day’s  Prophet’s headline read "'Brightest Witch’ casts shadow of doubt on Ministry." A nice turn of phrase.  