To dream of a hummingbird represents indecisiveness or "flightiness." You may have a problem making a final decision, or struggling to make a choice. It could also be a sign that you have a lot of options to choose from or want to experience a number alternatives.
Example: A young boy dreamed of a hummingbird flying in front of him. In real life he discovered that he needed glasses. The hummingbird reflected his conflicted feelings about where or not he wanted to wear the glasses.
Example 2: A young man dreamed of hummingbird flying in his room. In real life they were unable to decide whether or not to tell someone they had feelings for them.
Example 3: An old woman dreamed of a hummingbird shortly before her death. In real life she was debating whether or not to get baptized to please her family before she died.