Flip it around: Akrasia is the state of having flawed judgment about one's values. Of course the part of the brain that can speak always speaks highly of itself to the detriment of all the other bits of brain. The important thing is to convince all of yourself that something is worth doing. Telling yourself that you should do something is as persuasive as someone else chiding you to do it. Yes, the verbal, "planning" part of your brain has convinced itself, but it is also self-absorbed and treats the rest of the brain like its footstool.

For an example, "I should lose weight" is a ridiculously abstract concept to most of your brain. Your talky bit thinks it's saying something concrete: "Get that number on the scale down", but it hasn't actually said enough. It's a half-baked aspiration, not an activity. "I should exercise" is better: It prescribes an abstract activity that would accomplish the goal. It's still terrible though because it's still abstract. What is the value of exercise in the abstract? You don't experience exercise in the abstract: how could you possibly judge whether it is rewarding or not? How can you decide to "exercise" when exercise isn't even a real thing?

"I should run" is even better: You know how running feels. You can feel good running, and you can feel bad running. There are actual experiences and knowledge to draw upon to determine the value of running. Still: Not enough. Should you be running all the time? Verbal brain is being awfully sloppy, and has the gall to blame the rest of the brain for its mistakes. "I should run tomorrow in the morning for 30 minutes when I wake up." And we have arrived at remedy #3 which is called implementation intention. Honestly, what other intentions are actually intentions? If you're not planning concrete actions but abstract classes of actions, you're daydreaming, not planning. Verbal brain likes to talk about how important obligations and commitments are, but avoids doing the work of translating its precious thoughts into something intelligible to the rest of the brain.

The verbal part of your brain is easily convinced: By its own words. It doesn't even know what it has convinced itself of but it is awfully satisfied with itself. You, the ensemble of brain bits, are obviously skeptical of such a gullible entity. When you experience satisfaction or gratification for doing something, that is real knowledge to your brain; you learn what is good and what is bad. Of course you're going to prefer real knowledge over the ravings of an imbecile about the great rewards of not-even-a-real-thing.