We usually forget those things we don't really need to remember. Unless those were very special days, like Christmas or anniversaries, you probably won't remember. If you go back as far as your childhood, you can certainly remember some things, but only a few. You may remember your first day at primary school and your 7th birthday, but not every day at school or all the other birthdays. We often don't bother to remember things when the information is usually to hand.
Most people look at their newspaper or watch.
We even forget some of the things we really need to remember. It's normal to forget. Most of the time we can live comfortably with our limitations, including the fact that we forget. We accept that we can't usually see things clearly a mile away, hear the movements of insects, or lift a car. We don't mind that we can't remember every detail of our past life.