"Don't forget your old friends" 可以说成 "不要忘记你的老朋友"。

这个短语是指不要忘记和忽略你在过去已经交往过的朋友，即使你现在可能和他们并不经常联系。

下面是一些例句：

"Even though I don't see them as often as I used to, I still try to make time for my old friends." (即使我不像以前那么经常见到他们，我还是会努力抽出时间和我的老朋友们在一起。)
"I know we don't talk as much as we used to, but I still consider you one of my old friends." (我知道我们不像以前那么经常聊天了，但我仍然把你当成我的老朋友之一。)
"I'm so glad we reconnected after all these years. It's important to never forget your old friends." (我真高兴我们在这么多年后重新联系上了。永远不要忘记你的老朋友是很重要的。)