There are other books in the literature that mainly focus on how to go about proving things rather than proving specific things.
Some titles that come up are:
Mathematical Proofs: A transition to Advanced Mathematics by Chartrand, Polimeni and Zhang.
Book of Proof: Richard Hammack
Jay Cumming’s Proofs
I remember I once had a book that advertised itself as a book on Discrete Mathematics but it turned out to be more in line with the titles above, was a gem, if I find it I'll let you know.
But it's nice to see I'm not the only guy who gets a kick out of this stuff.
I wouldn't bother with things from the foundations of mathematics area, like Russel or Frege and whoever else came from that era, back when people still wrote an 800 page treatise on what a "number" even is. A lot of the material coming from that period seems to have been thrown down the drain.