Haha nice, Bert responded (and first time hearing about Nostr)! What nostr:npub1s6z7hmmx2vud66f3utxd70qem8cwtggx0jgc7gh8pqwz2k8cltuqrdwk4c already explained, there are different bridges between Mastodon, Bluesky and Nostr to relay all the content.

https://mostr.pub/ made by nostr:npub1q3sle0kvfsehgsuexttt3ugjd8xdklxfwwkh559wxckmzddywnws6cd26p so you can follow anyone from the fediverse (Bluesky, Mastodon and Threads).