The Marvel Cinematic Universe is a dense web of storylines, characters, and thematic elements. Moreover, there are seemingly endless amounts of MCU Easter eggs for audience members who pay close attention. These MCU connections may be small, but they flesh out everything from story points to character growth. And unless you have the gift of super-sight, you probably didn't notice them in the theater.
Marvel movies are full of bombastic scenes and amazing one-liners, but the best MCU moments remain those that manage to connect multiple films with a simple piece of information. The clue can be hidden in a line of dialogue, or a visual treat. Whatever the case, these tiny moments make the films that much better.