I want a feature where I can organize my questions/answers in my math.stackexchange profile by some custom tags created and seen only by me. I want this feature because sometimes I forget which questions I did not fully understand / which answers I think may need some revisions after re-reading it many months/years after.
My current solution is to create an online note from other sites and copy-paste each of my questions/answers and use the custom tags feature provided there, but if someone had 500+ questions/answers this would become hard work! If the custom tags can be created and only seen by myself (so it won't affect other users), then I can create tags like: "Need revision", "Not fully understood", etc. and I can filter those that interest me, for example: "Not fully understood" + "linear algebra".
I'm not sure whether everyone will need this but personally I think this is a very good feature. What do you think about this idea?