You probably don't feel guilty for failing to snap your fingers in just such a way as to produce a cure for Alzheimer's disease.
Yet, many people do feel guilty for failing to work until they drop every single day (which is a psychological impossibility). They feel guilty for failing to magically abandon behavioral patterns they dislike, without practice or retraining (which is a cognitive impossibility). What gives?
The difference, I think, is that people think they "couldn't have" snapped their fingers and cured Alzheimer's, but they think they "could have" used better cognitive patterns. This is where a lot of the damage lies, I think:
Most people's "coulds" are broken.
People think that they "could have" avoided anxiety at that one party. They think they "could have" stopped playing Civilization at a reasonable hour and gone to bed. They think they "could have" stopped watching House of Cards between episodes. I'm not making a point about the illusion of free will, here — I think there is a sense in which we "could" do certain things that we do not in fact do. Rather, my point is that most people have a miscalibrated idea of what they could or couldn't do.
People berate themselves whenever their brain fails to be engraved with the cognitive patterns that they wish it was engraved with, as if they had complete dominion over their own thoughts, over the patterns laid down in their heads. As if they weren't a network of neurons. As if they could choose their preferred choice in spite of their cognitive patterns, rather than recognizing that choice is a cognitive pattern. As if they were supposed to choose their mind, rather than being their mind.
As if they were already gods.
We aren't gods.
We're still monkeys.
Almost everybody is a total mess internally, as best as I can tell. Almost everybody struggles to act as they wish to act. Almost everybody is psychologically fragile, and can be put into situations where they do things that they regret — overeat, overspend, get angry, get scared, get anxious. We're monkeys, and we're fairly fragile monkeys at that.
So you don't need to beat yourself up when you miss your targets. You don't need to berate yourself when you fail to act exactly as you wish to act. Acting as you wish doesn't happen for free, it only happens after tweaking the environment and training your brain. You're still a monkey!
Don't berate the monkey. Help it, whenever you can. It wants the same things you want — it's you. Assist, don't badger. Figure out how to make it easy to act as you wish. Retrain the monkey. Experiment. Try things.
And be kind to it. It's trying pretty hard. The monkey doesn't know exactly how to get what it wants yet, because it's embedded in a really big complicated world and it doesn't get to see most of it, and because a lot of what it does is due to a dozen different levels of subconscious cause-response patterns that it has very little control over. It's trying.
Don't berate the monkey just because it stumbles. We didn't exactly pick the easiest of paths. We didn't exactly set our sights low. The things we're trying to do are hard. So when the monkey runs into an obstacle and falls, help it to its feet. Help it practice, or help it train, or help it execute the next clever plan on your list of ways to overcome the obstacles before you.
One day, we may gain more control over our minds. One day, we may be able to choose our cognitive patterns at will, and effortlessly act as we wish. One day, we may become more like the creatures that many wish they were, the imaginary creatures with complete dominion over their own minds many rate themselves against.
But we aren't there yet. We're not gods. We're still monkeys.