I sometimes get some amusement with people with this attitude. Just play the 'How' game.
Basically, ask them, as earnestly as possible, HOW do you focus? You'll likely get some rote answer, that's when you start digging. Acknowledge the obvious bit and drill into the difficult bit. They will quickly be left stuttering with a "you just do it" type response. See how long you can keep it going.
The more honest, earnest and even slightly desperate you are, the funnier it becomes. They just told you they have the secret to fix your life, but now won't share it. WHY won't they share?!?