A topic that I will remember most is about how our brains think (biological psychology). It is interesting that the right hemisphere of the brain works for the left side and the left hemisphere works for the right side of the body. I always found that to be interesting, although it may be an awkward concept to keep in mind, but I find that it actually might come in handy for the future. I say this because I know that as you grow older, there will probably be more troubles to your body such as strokes, brain damage and such. An example of this is when a patient goes through split-brain surgery and they become "blinded" to some things on the left or opposite side. Also with people who have brain damage on a certain hemisphere, it would be helpful to know what body part or function in your body won't be working.
If I had to damage a side of my brain it would probably be the right hemisphere which functions the coarse language skills and visuospatial skills because I rather keel the actions. The brain has so carries so much information it could be an endless conversation. Of course, there are many interesting things that we should all know about the brain and this is just one tiny bit of information.