To Crack An Egg In the Middle of Dinner

Colloquialisms are short, simple phrases that people often use without realizing that they are using them. These phrases often don't make sense, but their meanings are commonly accepted and agreed upon by native speakers of the language of the colloquialism.
Let's begin with my personal favorite colloquialism; go to dinner. Let's examine this little tidbit in detail. The word 'dinner' refers, in this case, to an event and not a place. Yet, there is an unspoken reference that the event known as dinner will not take place where you are but in an entirely different location which may or may not have been determined previously.
The phrase 'go to dinner' is slightly similar to the phrase 'crack an egg' because technically the only part of the egg you crack is the eggshell. However, we wouldn't say 'crack an eggshell' because that would be unnecessarily complicated. It's enough to say 'crack an egg' because the first part of the egg to be impacted is the shell and once there is a crack in the shell that's really the end of it.
Another common colloquialism is the phrase 'start the car.' A person not familiar with cars would be inclined to ask what to start the car doing. The true intent of this phrase is that the car is to remain relatively at rest while the engine begins doing whatever it is required to do for the car to accelerate. In fact, many people have abandoned this phrase for the more precise 'start the engine.' For example, in races like the Indy 500 the track announcer says "start your engines" before the flag is waived. If the command was 'start your cars', people would have to start their engines and then accelerate. This would obviously give an unfair advantage to the drivers with faster starters in their cars.