I shock my friends and family when I can tell them from memory their phone numbers from 40 years ago. 12 words is not actually difficult, what I find difficult is not worrying that I might forget them somehow or mess up just one of the words over time.
Discussion
I heard one thing today somewhat related to this that has really stuck in my mind. If I understood correctly Hal Finney was cryogenically frozen and in the future when the tech allows it will he still remember his seed phrase when reanimated?
This is actually incredibly risky IMO. If you're hit in the head or have a particularly rough night or get old or catch a disease then you may survive but forget your codes.