[D hums, letting Leon settle somewhat before he moves his fingers again, working into a particularly tense spot. He's still listening to Leon's woes about... being dumb, more or less, but most of his focus is on what he's doing with his hands. For whatever reason, he's being allowed to do this...]

The older you become, the more difficult it is to learn a new language. Isn't that how it goes? [He wouldn't know, considering.]

When have you tried to learn a new language before?