memory loss or just serious forgetfulness?

i jus got to know something.....i recieved a call last night. What's so surprising or alarming about that? Well, the thing is i didn't know...to be exact, i don't remember(ah...lost that little part of my memory). What's happening to me? i can't even recall on recieving any call from anyone last night. What if it was something important? and i don even remember the call, not to mention what i replied or say to the person who called. I think i'm really on the brink of going nuts. My memory is deteriorating even faster than i think....and i'm jus barely 18. I won't mind if this is the first time.....to be truthful, this has been going on for quite some times already. I also keep on forgetting where i put things and the things that i should do. At times, i run from downstairs to upstairs, jus to forget what i wanted to do when i reach the top....i know this isn't genetics, so what is it?