Things I learned after 25: Memory fades.
>> I take my memory for granted.
You will start to forget very basic things as you get older - things you said you'd never forget. Suddenly you can sympathize a little more with the sitcoms characters who forget birthdays and anniversaries. Sure, our day to day recall has been damaged by the over reliance on Google searches but it's the forgotten milestones, trips, celebrations, etc. that is really startling.
With the influx off efficiency apps, social connectivity, and over-optimization of, well, everything, you rarely need to activate the little memory chambers in your brain for much. But there are certain things that don't have a wikipedia page or a staff of contributors creating blog content around - and those are your personal memories and experiences. With this sad realization that things are being erased from your own personal memory bank - things that only you care about, there's the revelation that you need to actively recall and restore your own memories. Plus, it's a fun exercise. Log out of Facebook, call up your friends or family and reminisce.