I think one nice unintended consequence of searching for old posts being difficult is that I tend to rewrite variants on long posts I've made in the past after a while, instead of just resharing them or avoiding since I already wrote on the topic.
I like this because it mimics the natural pattern of retelling the same story to different folks (or even the same folks). It helps refine the thought behind the post, shares it with new people, and helps me keep that thought fresh in my memory. It's a nice little pushback against the obsession over all new content needing to be (or appear to be) new and unique.