Joy from all angles. With titbits and tidbits, which you might or might not have known, like for example we still didn’t proof whether or not there are slightly excessive numbers. Useful for understanding numbers, useless according to dandy Hardy, touching the why off mathematics.

no man’s land is strewn with numbers

kr=, a couple of seconds ago (or I’m unaware of citing somebody; if so, please enlighten me)

Another angle is the history of Fermat’s last theorem from the ancient times to its proof, growing the construction of the proof. And the growing pains of proofing.

It also shows the sometimes nearly invisible line between hero and zero, where the prover thinks zero and the writer rightly, and little seen, screams in silence how great Wiles’ contribution would have been even if he hadn’t been able to take the last step in the proof.