I had someone ask me recently how I managed to move all my 10 years worth of notes from Evernote into my new system in Notion & then into Roam Research.
The truth is, I didn't. I literally abandoned everything in Evernote and started again.
Here's the cold hard facts, I didn't look at those 'old' notes anyway. I used Evernote as a way to clip things I thought I would need sometime in the future - except when it came to the future, I didn't actually need any of them.
This might seem like some drastic Marie Kondo stuff if you're currently a digital hoarder (like I was). It really comes down to a change in your mindset around knowledge:
Mindset 1: There 'must' be some gold somewhere. Looking at a big pile of notes and thinking there might be something good in there is like looking for a needle in a haystack. The truth is your life is totally fine right now not knowing about that random note you saved. So forge on into the future and leave those notes in the trash.
Mindset 2: I might need it one day, so I should keep it around. But how do you really know what you will need in the future? Up until now, you've proved that theory mostly wrong with a pile of notes you don't use 'in the future.' So burn those notes and let's move on.
Here's the mindset you need to embrace: There is far better knowledge ahead than any you have forgotten behind you. We live in a world of infinite knowledge (you couldn't get through it if you tried), so embrace the fact that your knowledge is building every day and you don't need some odd note from 2008 that you can't even remember exits right now.