3种回忆和怀念过去英文 - 这些英文怎么用 
1: In retrospect 现在回想起来
（常用于对过去的事或人有了新的观点或认识）
eg: In retrospect, I should've studied harder. I couldn't see it then, but I see it now.
2: reminniscing 追忆往事
eg: I've been reminiscing(about the past) a lot.
3: Nostalgia n. 回忆、思念过去某一情境的感觉
eg: This dish is giving me so much nostalgia. I'm tasting my mom's cooking right now.