I was always confused as to why Edmund says in the Prince Caspian movie, "So you're bravely refusing to fight a swordsman half your age," when Miraz was probably three or four times Peter's age. But then I remembered: Edmund saw Peter live up to his twenties in the Golden Age. If Miraz was at the very least forty-years-old, then chronologically, Edmund's statement makes sense.
Additionally, by the time of the Telmarine Age, everyone and I mean everyone, would know of the Kings and Queens of the Golden Age. They knew they would be in their twenties when they disappeared, but when they returned as preteens/teenagers, of course the Telmarines would underestimate them and forget they are actually much older. Miraz and his men were thinking they were having a war with literal children. But Edmund's sassy statement would've brought Miraz back to reality. Miraz choked up because he remembered who he was really up against. Edmund's words reminded Miraz not to underestimate him and his siblings. "We're actually much older than we look, so if you think you can get away with this, you won't," is basically what Edmund said lol
This also shows how very intelligent and word-savvy Edmund is. No wonder he's the diplomat. No wonder they chose him to deliver the challenge to Miraz.
(Or maybe Edmund just forgot him and his siblings were back in their preteen/teenage bodies, which was why he referred to Peter as only half the age of Miraz. But either way, he clocked Miraz HARD lol)