"Someday I will need this.", "Eventually someone will want to see that.". What do you tell yourself as you approach your clutter and memories? I know that I am rare because I don't have a hard time getting rid of things that may be difficult for most. Many are very attached to sentimental objects that they assume will eventually bring sentimental value to their future generations.
Because my approach is not the same as most, I offer a simple guideline when approaching your clutter, "Will I want to show this to my grandkids? Will my grandkids care about this when I show it to them?". For me, if the answer is "no", I do not hold on to it.
Clearing the clutter from my home and life is very important to me, but this does not mean there is NOTHING that I hold on to. The outfits my girls came home from the hospital in, yearbooks, and special mementos are special to me and I keep them together in organized bins. Occasionally I do go through these memory items to reevaluate their "value". There are things you keep thinking they were from a critical time in your life, but with some perspective, it may have less sentimental value than originally thought.
For the LOVE of your posterity, DON'T keep everything. Going through the clutter of loved ones who have passed on is not a fun experience, but viewing treasured and well preserved items set aside for your viewing is.