Since it hasn’t been mentioned yet, another way to parse through and figure out what you do vs. don’t remember would be with this userscript:
You can adjust the settings to review radicals/vocab/kanji from specific levels or specific stages. I took a one-month break at one point (when I was around level 13) and used this script to review everything from every level before tackling my lessons and reviews. I had the feeling I had forgotten most everything, but after reviewing I realized, with much relief, that I remembered pretty much everything, apart from kanji and vocabulary from the most recent levels I had covered, as well as some leeches. And when you compare that to SRS stages, it makes sense that the material I had reviewed earlier and committed to long-term memory would be the stuff I’d have an easier time recalling. After finishing that (it took me about a week), I began doing reviews again (I had turned vacation mode on so not that many to tackle), and made it a point to fail anything I didn’t immediately remember (since the SRS will take care of it down the road).
Don’t get down on yourself before you’ve properly assessed where you stand. Every time you come across something you don’t remember it’s easy to fall into the trap of thinking you’ve forgotten everything, but what we don’t tend to consider is how much we really still do know and remember.