Improvement makes yesterday’s impossible look incorrectly labeled.

Once you can do something, the label you had on it turns out to have been wrong rather than the situation having changed. It was never impossible. It was beyond you at that time, which is a different claim and a temporary one. Most personal limits are stated with far more confidence than the evidence supports.

Go back to something you decided you could not do a few years ago. Look at it now with what you have learned since. Some of those will still be out of reach and at least one has probably been mislabelled all along.