Users should keep a local copy of their public notes.

For example, by paying 5 sats, a relay would commit to storing it for one year. If after one year, the user deems the note to be very valuable, they can resend it, essentially renewing it. Notes that the user considers not valuable do not need to be resent. nostr:note1sz3dl303ttzhlef8fuyhsyhjh8e288ghzsjhsd9ldq55g7qqnjwq7zghft