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?!?
Then I spend about 30 minutes forcing myself to do whatever task until it no longer is forced.
Ok, HOW do you “force yourself”? I can do it for tightly aligned tasks, for a short period, but burn out rapidly. Back at university, I managed to induce heart arrhythmia pushing myself this way.
It also doesn’t help with the initiator issue. HOW do you get yourself moving in the first place? I can reliably do it a couple of times a day, but day to day life needs more than that for basic maintenance.
Oh, and don’t get me wrong, I’m functional, but it runs me at my mental limit all the time. Parenting pushed that to the next level. I’m permanently riding the knife edge of burnout.