It happens to everyone occasionally, and to others more often. It runs in my family--all of us, some worse than others. My father writes lists before hand to remember what to do. My mother, before she passed away, used to write lists afterwards to remember what she had already done.
I and all 3 of my sibs tend to be forgetful. I used to think I was the worst, but then found out that my older brother is the worst. He will put food in the microwave, turn it on, and then go out and drive away on an errand. He will take something out of the fridge and forget to put it back when he's done with it, so it sits on the counter for hours and then needs to be thrown out. He forgets important stuff at work. I won't tell of his biggest work boner. If it ever got back to him, he would be furious. He is very, very absent minded.