When I thought it was already an old forgotten thing, that I suddenly dreamed vividly of last night?

maybe ur currently feeling something like what u felt before even if its not the same situation... for example if u've started seeing a new guy u might suddenly have a dream about one of ur ex's or a person u loved a long time ago. even if u r over them, it could just be a way of ur subconcious mind trying to express it hopes or fears of the future