General Missing Out:
* Missed the bus: This idiom emphasizes missing a specific opportunity.
* Missed the mark: This idiom implies failing to achieve a goal or meet expectations.
* Missed the train: Similar to "missed the boat," this emphasizes a lost chance.
* Left behind: This idiom suggests being out of touch or not keeping up with current trends.
* Out of the loop: This idiom means being unaware of important information or events.
* Too late to the party: This idiom indicates arriving too late to participate in something enjoyable.
Specific to Missed Opportunities:
* Too little, too late: This idiom suggests an action is taken after the opportunity has passed.
* Lost the chance: This idiom directly states that an opportunity has been missed.
* Let the opportunity slip away: This idiom emphasizes the missed chance due to inaction.
The best idiom to use depends on the context and the nuance you want to convey.