Depends what you want to get out of your log. Some folks, like me, want to know every detail of a dive site, their weight, temps, etc for years after the dive. In fact, I've answered questions on SB simply by looking at dives done years ago. If you really believe you will never need the information again, then do as suggested above. Log just enough needed for certifications. For myself, I really enjoy going over my comments from years ago to see how I've changed.