1. to reorganize (as after a setback) for renewed activity.
2. to stop for a short time and prepare yourself before you continue doing something that is difficult: to stop and think, reorganize, etc. before continuing.
Life consists of events that do many things, one of which includes causing people to regroup. Certain events and people are mere footnotes in the bigger scheme of things, a collection of sentences helping to form a decent paragraph on a page; a forgettable scene in the movie of one's life.
Other events and people are much bigger; the collection of sentences form a mere page into much more. A single page becomes two, two pages become three, three pages transform into several, and several into a chapter. Soon, the chapter becomes paramount to your story; the scenes containing the authenticity to create a classic film.
It's not too difficult to regroup when the former is the case. But what about the latter? What about when the latter takes on a life of its own, unplanned and unforeseen, to the point where elements converge and become such an integral part of your story?
Does a person ever regroup from that?