PSA about Unsealed Spellbook

You have to click the little arrow that appears above your summoner spells to switch to pick another spell. Also you have to be out of combat.

Seriously, I recently had two different games where someone had Unsealed Spellbook and NEVER USED IT ONCE during the whole game. Like wtf you might as well take Glacial Augment (lol) if you're not gonna use your keystone.