"Well, in terms of practice, the obvious thing to try is writing down notes to yourself about which thoughts you're having, and then asking yourself, for each of those thoughts, if there's any good reason not to explain it out loud to Ramona."
"But of course if your character is playing straight the trope of the ancient-wizard-tackling-relationships-for-the-first-time-who-undercommunicates, you may first need to have a long conversation with yourself, or with Ramona, about to what extent you believe that it's now safe for you to talk about more things with her. Ramona may need to go on some sort of subquest about that, about proving it to you or figuring out the right experiment to run; she's probably the main character given that more information is being concealed from her."