In the game of life, these same 3 categories of errors also exist. Inaccuracy: There are choices you make when you fail to strengthen your position- maybe you slacked off during college instead of studying. Mistake: There are choices you make when you weaken your position- perhaps you compromise your standards. Blunder: There are choices you make that cost you dearly- perhaps an extramarital affair.
A chess player has many opportunities to play and improve. What about in life? When you are young, your parents should serve as your life coaches. They should give you opportunities to make the 3 types of errors and talk through them evaluating how things would have turned out had you made a different choice. To improve at chess and life, you must pay attention in times of practice and preparation (childhood and youth), so that your tournament play (adult life) is at its best.