I don't think "my lack of guile" fits. Guile is deceitful cunning, more what the pickpocket had. Day-dreaminess or lack of pragmatism is the victim of that.
I too am not sure about the point of the Spanish there, though I can understand it. I get it that the N is having fun using it while touring, but I'm not seeing how it adds to the poem.
And the brain simile earlier in the poem is problematic. I like it that the facade blossoms like a brain, but then it becomes a double simile ("Like Gaudi's," "like mine"), which strains a bit too much imo.