It is a habit of the mind to wander. What happens when you sit quietly for a few minutes trying to think about something, or just sit down to relax? Next time you do this, try to watch your mind, and you will discover that it flits around like a butterfly, going from one thought to another.
The mind keeps thinking, worrying, asking questions, answering, giving excuses, telling stories, imagining, creating problems and solving them.
This happens not only while you sit down to relax, but also while working, driving, cooking, eating or doing anything else. This non-stop activity weakens your ability to focus your mind, and as well as interferes with your ability to deal effectively with what you are doing at each moment of the day.
A wandering mind can prevent you from falling asleep, finishing your tasks and work, and completing what you are doing. It also wastes your time and energy, and can be tiring sometimes.
Some people would tell you that if you perform more than one task at a time, you will save time and get more done. This might be true at times, when carrying out automatic tasks that do not require your or attention, but you will get done, and more accurately and efficiently, if you focus on just one thing at a time.
How many times have you tried to do several things at the same time, but ended doing mistakes and then having to correct them? When you focus on one task at a time, you do it more efficiently, easily and quickly. Paying your undivided attention to one subject is a sort of meditation, and this action teaches your mind obedience and discipline. When your mind is obedient and disciplined, it stops wandering, and you are more at peace.