sylvia on flashbacks

i like this way of showing flashback from Harry Potter movies - "Anyone can examine the memories in the Pensieve, which also allows viewers to fully immerse themselves in the memories stored within ... ." i want the character to stay in the here and now while having the flashback. i hate it when the character, me and the story lose track of the throughline for the sake of a flashback. ah, well - off on another storytelling adventure.
sylvia