An important aspect of self-image is whether people consider themselves "successful" or "losers", based on their previous successes and failures. But we have a bias here: the feeling from a successful or failed task is not proportionate to its difficulty. So people can manipulate their outcomes by only doing easy tasks, which have high success ratio. When used strategically, this can be helpful; but doing it automatically all the time is harmful. Learning new things requires trying new things, but that has a risk of failure, which can harm self-image with possible bad consequences such as learned helplessness. On the other hand, protecting self-image all the times means never learning anything. Updating means admitting you were (more) wrong. How to deal with this?

When you practice or learn, ensure that each session ends on a high note. Either push yourself to accomplish something for the first time and then stop immediately, or end with an exercise that you find difficult but now comfortably within your abilities. This is, apparently, commonly used in animal training -- see the "laws of shaping".

I suspect this works because of the peak-end rule -- even if you've been working above your comfortable difficulty for most of the session, you'll remember the session as if you did difficult things, and became more competent by the end. You won't remember the session as frustrating or painful if the end is especially satisfying.