No Spoliers but an excerpt from A Clash of Kings.
Lord Rowan beside her did not join the merriment. "They are all so young," he said.
It was true. The Knight of Flowers could not have reached his second name day when Robert slew Prince Rhaegar on the Trident. Few of the others were very much older. They had been babes during the Sack of King's Landing, and no more than boys when Balon Greyjoy raised the Iron Islands in rebellion.
They are still unblooded, Catelyn thought as she watched Lord Bryce goad Ser Robar into juggling a brace of daggers. It is all a game to them still, a tourney writ large, and all they see is the chance for glory and honor and spoils. They are boys drunk on song and story, and like all boys, they think themselves
immortal.
"War will make them old," Catelyn said, "as it did us." She had been a girl when Robert and Ned and Jon Arryn raised their banners against Aerys Targaryen, a woman by the time the fighting was done. "I pity them."
"Why?" Lord Rowan asked her. "Look at them. They're young and strong, full of life and laughter. And lust, aye, more lust than they know what to do with. There will be many a ******* bred this night, I promise you. Why pity?"
"Because it will not last," Catelyn answered, sadly. "Because they are the knights of summer, and winter is coming."
END exerpt.