Have you ever inherited a skill and then discover you can't use it? (Yes, I'm an idiot)

I just wasted the only Attuned Caeda I had because I really wanted to have Guard Echo (alongside Mayhem Aether) on Fallen Ike. I speed past the warning without reading like an idiot and now I face the consequences of my actions: 0 Attuned Caeda fodder, no Def/Ref Pledge/Doubler for anyone.

(Yes, I can still use Guard Echo with something like Godlike Reflexes on this Ike, but that's not what I wanted)