The word "experience" has two meanings, one is literal: something someone has been through before; the other is more figurative, refering to the knowledge/skills etc. gained from past experiences. When the word is literal, it is a countable noun. When it is figurative, it is uncountable. Let me tell you how to distinguish these two meanings: for example, in the sentence "he has a lot of experience", "experience" remains singular after "a lot of", inferring that it is an uncountable noun. Therefore, in this case, the use of "experience" is referring to the figurative meaning. Similarly, if you find "experience" in its plural form, or after indefinite articles such as "a" or "an", then you can tell it is countable, thus referring to its literal meaning.
难忘那缕羁绊
