Memory

I had an exam at the end of the last week and its following weekend means nothing but weekend and enjoying it without feeling guilty of getting engaged in those businesses that are not really related to the pending tasks.
I've had 7 modules so far and one thing has been happening after taking each exam and has come to my notice now. I take the exams on Thursday evenings, then it doesn't matter if I sleep at 9, 10,11 or 12 at night, the next morning exactly at 4-5 I wake up with one of the questions that I faced the day before as if that question is whispering itself into my ears and I automatically think about the answer that I wrote and this goes on till I fully get back to my consciousness and start to feel that I'm not asleep anymore. It's not like I was thinking about that specific question the night before and I've never been like this as long as I can remember.
The last term the topic was about memory and its underlying mechanism. Apart from neural events that form our memory traces what makes matters get stuck or erased from our mind is the amount of "attention" we pay on them and I was thinking how efficient could be if we had this capability to notice to those things that are really worth noting, imagine if we could actually see nice words and kind gestures from people around and not those' who don't care about others' feelings, how incredibly free our mind would be then when no strong traces of the bitter feelings could be found later.
One more thing, I have this ability to get lost so easily, I've never been good at directions and apparently for this not so great spatial memory of mine my Hippocampus is to blame but it can get bigger and for that I need to pay attention much more or become a taxi driver as apparently they have big Hippocampuses ;).