<p>I do remember Thomas in high-school. </p>
<p>It sounds like math was harder way back when. There’s an interesting review at Amazon for Spivak’s book on where math is today. I don’t think that that many schools use something like Apostol or Spivak for their honors classes anymore. Most of the common textbooks today are heavily application-oriented. There is no assumption that students know how to do proofs when they get to college.</p>