回想起来，那真是个惊奇的旅行

come to think about it,that was definitely(really ,absolutely)an odyssey.

odessey 有冒险的意味在里面，如果只是惊奇没有危险的话，an amazing(eye-opening,once-for-a-life) journey(trip),

回想起来
不是很清楚怎么翻译
那真是个惊奇的旅行
It's really an adventurous trip.