First of all, I would like to tell you that I really enjoyed my stay and it was a unique experience for me.

unique 来自拉丁语 unicus，由词根 uni-（表示"单一"）和形容词后缀 -que 组成，字面意思是"唯一的、独一无二的"。在现代英语中表示"独特的、与众不同的"，强调某事物具有不可复制或难以比拟的特质。