Can there be a way to hide my mastery?

Awhile ago I tried to learn top lane because it was the only lane i didn't know and I figured I would try to learn Riven since she couldn't be as hard as people say she was, and I did horrible but I played alot and got lv 5 because its easy to do if you spam a champ but I somehow got lv 6 off of some lucky games, and I gave up (played fio and loved her) for awhile and want to learn her but people expect me to be good and just get angry when I don't so wanted to know if there would be a feature where I could hide that mastery 6 at will