Short term memory lapse in 18 year old

Im 18 years old and have recently been having a strange sensation. It's difficult to describe, but Im going to give it try. The first symptom is frequently becoming suddenly aware of my surroundings. The only thing I can compare this to is standing up too quickly and "browning out". The sensation you get the instant you return from the blackout is what I'm experiencing. If i think about it, Im able to recall all of the details of how i got where I am. However, the strange part is that it doesn't feel like it was part of the same moment, but instead like I'm trying to recall yesterdays events. Its like a brief lapse in my short term memory. Having to consciously try to remember the previous events and there significance in my life is very unsettling.
The second symptom is that live events don't fully register with my brain. Life feels much more like a movie than reality, and I have almost zero sense of self. I will be in a place and every so often it will occur to me that the event is actually taking place. I should state however that Im in no way depressed, just that nothing quite feels real. Physical exercise seems to temporarily stop all of the above symptoms, and Im active as often as possible.
I know Im not giving you much to work with, but any advice would be helpful. Im basically asking if you think something is wrong, or if Im just becoming an adult.
Much Thanks

[margypops]

Are you on any Meds or taking any supplements?How is your eating ,when you feel these episodes are you hungry or have you recently eaten,any new happenings recently, happy at home .friends etc Are you drinking enough water and not getting dehydrated as that along with Exercise and in Summer can happen a lot.Yes and finally you are becoming an adult Welcome to that glorious world.

[tina1994]

i have recently been suffering the same symptoms too, and have now been able to put my symptoms down to stress, even though i didnt think i was stressed, and showed no other symptoms except being far away from my head and not being able to recall anything i had just done or said my brain was stressed.
i found changing my food habits and drinking more water helped a little.

hope this helps

tina