"Fell into place" is an idiomatic expression that implies a sense of order, clarity, and harmony. There are several synonyms for "fell into place," including "came together," "jelled," "coalesced," "aligned," "fell into line," "concurred," and "fell into a pattern." Each synonym has a slightly different nuance, but all convey the sense of things falling into a cohesive, understandable order. Whether it's arranging a puzzle or organizing complicated ideas, the sensation of things fitting together can be exhilarating. With any of these synonyms, you can describe how something has come to express coherence and order, and how this has improved your understanding of the situation at hand.