Every note is just a text file stored on some server. It's not on the blockchain. Servers go down, files get erased or lost. Unless you keep a copy of that note yourself, others have no incentive or obligation to store it for you.

Zaps happen on lighting, which are just notes passed back and forth between people. They aren't on the blockchain either. When a channel gets closed, all the records of zaps get thrown out too, and only the final balance between people is recorded on the blockchain. It's extremely unlikely that a channel you use now will still be up 30 years from now.

Finally, when you create a note, I think you can backdate it to prior time and pretend that there was a zap involved? Though I'm not sure. It's just a message signed by a private key, so I don't know if there's anything to stop you from creating false but signed messages.