Everyone can be forgetful just something our brain does and we just don't remember everything so it isn't anything serious unless you are older of course there are reasons why.
You are young and I can remember saying things to my son why are you forgetting to do this or that but remember the things that make no sense lol but to him they made sense .
I walk through the house and forget what I am doing but I don't worry about it and I misplace things then find them and if not I just don't stress about it . People with anxiety, panic, depression we focus more on fear and then we do forget other things but only because our minds are stuck into thinking a certain way that is when we retrain the brain .
Keep the mind active we only use 10% of it so just imagine all that ***** left to use! :)