Yes, very. I occasionally have a day where I cannot remember my master password for my password manager. Often after a prelonged break or change of context.
It is tricky, but genuinely forgetting the key and seed may be regarded as an unintended outcome, and it is a reasonable ethical principle that people who commit crimes can be held responsible for unintended outcomes. For example, the people who want Boeing executives jailed for the 737 MAX crashes are taking that position, and the concept of manslaughter is an explicit manifestation of the principle.
Commit crime, and pay for unintended consequences principle looks quite reasonable, but it's not what this law is about AFAICT. "Commit crime" part means it's already proven. This law seems applicable to someone who won't produce a key for prosecution to look for evidence against him. IANAL, but in many countries it would be seen as aggressive infringement of constitutional rights.
You can phrase it the other way: if you can make restitution, you get a lighter sentence. You can also make recovering the funds without making restitution a separate crime - and that can be extended to any windfall profits on your 'investment', as legally they were not your investments.