We can talk about pre-experience (i.e. the period before an experience begins), and post-experience (i.e. the period after the experience completes), but is there a word that describes the period during an experience? Is 'intra-experience' acceptable? Or is there something better?
Flow - a state of complete immersion in an activity
Along the spectrum of being in the moment, experiencing "the now", flow is the greatest of the qualities that could be used to describe experiencing the present. A lesser quality might be described by the phrase "being in the moment" or lower still, "being zoned out". Other than describing the quality of the moment being experienced between pre-experience and post-experience however, I don't know of a specific word that could best describe all types of experiencing the present.