The WORST thing that he could do is admit that the boos bother him. However, constantly reminding people that the boos don't bother him is

. It's like he's trying to convince himself to everyone else that the boos don't bother him. If you're still mentioning in your promos in 2015 that the boos don't bother you, they obviously still do.
After he got those "you can't wrestle" chants for so many years (which was a completely false chant to direct towards Cena), he started incorporating random flashy moves into his repertoire. That's no coincidence.