Is physical pain only 'remembered' or 'anticipated' so actually there is no pain? If so, how to understand?
In the Buddha's teachings feeling is of three kinds: pleasant, unpleasant, neutral. Feeling is dependent on contact with the senses: sight, smell, taste, touch, sound, mental object ( idea, thought, other) 


  "An untaught worldling, O monks, experiences pleasant feelings, he experiences painful feelings and he experiences neutral feelings. A well-taught noble disciple likewise experiences pleasant, painful and neutral feelings. Now what is the distinction, the diversity, the difference that exists herein between a well-taught noble disciple and an untaught worldling?


To see the difference read the continuation here: Sallatha Sutta: The Dart (SN 36.6)