Project management, why do we need to learn this course?

This is a critical question  for any manager  that works with new projects only in a daily basis.
A lot of workers are good at their specific field. However sometime workers need to do work outside their field and project management maybe one of these requirements.
Since I started my project management class, I have asked several managers  for examples of general uses of project management in their departments. The following are their responses:
1. Creating a project charter to explain and to see the objective of this project.
2. Developing and maintaining schedules
3. Work distribution among the team.
4. Monitoring performance of a project in terms of cost, time, and what was agreed on.
5. A general way to be organized and to encourage organization
6. Creating lessons learned documents to understand what went right and wrong

For me when I started studying project management I found out it was very helpful when it came how you need to enhance your communication skills, how to plan a project and even working with other workers from different backgrounds and also how the way they think to execute the project in hand.

At first let me explain to you what is project management?

Project management: is the process and activity of planning, organizing, motivating, and controlling resources, procedures and protocols to achieve specific goals in scientific or daily problems. A project is a temporary endeavor designed to produce a unique product or a service.

We all use project management outside work. For example, if you are planning a trip to go with your family you need to use the same steps as if it is a project. First you start to plan with your family where is the location of the trip. Second when will it be suitable a day to have the or when is everybody  free to go. Finally how much the trip well cost.

In this class I was required to do a field project in a very short time (three weeks) so I started to see if I can find a suitable group to work with which thankfully I did. Our group had a lot of great ideas to start with but due to the short of time we had to be very careful to choose the right idea with least risk in hand plus to have a backup plan in case something went wrong for the first project. Day by day thankfully the project went well because we had a very good understanding among ourselves and we did a very good job planning. We discussed the pros and cons of this project and we distributed the work based on the teams skills and talents.

In the end i learned  that project management is one of the essential courses to teach students or workers of how to achieve or implement good project and it can even be used in our day to day life.

In your opinion what will be the result if managers did not learn about project management?