Why cant i remember things is this normal?

I have always been forgetful but the last couple of years its gotten worse I forget to do everything like turn the oven off or that I was going to hang out with my sister just everything but I do eventually remember like a couple days later or if someone reminds me but the last couple months somethings I don't remember at all like some will say remember that time we did this or went here and I don't remember at all what is wrong with me I'm only 20