Of course I have them backed up as well.
All the typical ways. But my PRIMARY way is my memory.
Anyway, this is how I did it. (I'll use a 12 word seed as an example, but I actually did it with a 24 word seed phrase as well. It's a bit harder, but I used the same system I outline below, modified for 24 instead of 12 words).
If you want to find someone who will advocate seed memorization idea, it's me. Lots of people here vouch against this idea and I completely understand that but I like it because no one steal it from your mind, it's the safest place in the world but in your case, to be completely frank, it was a bad idea to remember 24 words seed phrase because 24 words is just too much and it's also unnecessary. If you are afraid of attack, keep in mind that 12 and 24 words are both equally safe, so, just focus on 12 words if you really plan to stick with memorizing it. The risks of forgetting 24 words doesn't outweigh the cons of 12 words because both are simply uncrackable right now.
I still repeat my seed phrases in my head every morning when i wake up, it's a fun little ritual I have. And havent had to look at that single card for a loooong time. Eventually I burned it too.
Anyway, that's how I did it.
That's how I do it too. Repeating my seed phrases every day.
