You can't teach an old dog new tricks!你没办法教老狗玩新把戏.
该句就是"老狗玩不出新把戏",比喻上了年纪或已经变成老油条的人失去了创新、求变的能力.
Girl: Mom, I was thinking about getting Dad to dress in cooler clothes...
妈,我在想要让爸爸尝试穿着较新潮的衣服...
Mom: Honey, don't even try. You can't teach an old dog new tricks.
亲爱的,别试了,老狗是玩不出新把戏的.