Ugh this is such a problem with me, I embarrass myself constantly with it. Umm concentration I try to give myself something to do with my hands, so to pay attention during a boring lecture I play with play-doh for example. Taking a class with a (studious) friend is also very helpful for grounding me and bringing my attention to what's going on. Really if you can get help from people around you that works great, or at least it does for me.
Memory....write everything down!! Anything I don't write down in my calendar I forget to do or go to. Often I even forget to check my calendar so instead I set an alarm to go off when I have to do something! As for short term stuff like remembering where I parked or where I put something I actually have a voice that helps me with that o.O Yeah I don't know. Mainly write stuff down. Oh and with medication I remember to take it by placing it somewhere that I will definitely walk by on my way out the door so I will see it and remember to take it.