My Dad always insisted on finishing our task rather than keeping it unfinished. This is very important lessons in life. I have seen people delaying things or in habit of carrying over. What I learn that the thing that we undertake, must be finished on time. Even in our vedas, there is special mention to finish three things in particular. These are enemy, fire, and debt. The verses that goes along is
अग्निः शेषं ऋणः शेषं शत्रुः शेषं तथैव च|
पुनः पुनः प्रवर्धेत तस्मात् शेषं न कारयेत्||
Agnih shesham rinah shesham shatruh shesham tathaiva cha.
Punah Punah pravardheta tasmaat shesham na kaarayet.
Agni = fire.
Shesham = remaining, left over. Rinam = loan, debt.
Shatru = enemy.
Tathaiva = similarly.
Cha = also.
Punah = again.
Pravardheta = grows, increases.
Tasmaat= therefore.
na = not.
Kaarayet = cause to do.
These lines highlights the necessity of finishing it says : "If a fire is not put off completely and a debt not repaid in full and allowed to remain, and similarly an enemy is not conquered completely and let off after a fight, all these three have the tendency of again and again growing in size and become problematic. Therefore, it is prudence not to permit any remnants of all these three."
The three things mention has alwsys remain a pain. Unfinished tasks can clutter our mind and limit our ability to think creatively, solve problems, and reflect on yourself. Not finishing a task can lead to intrusive thoughts and a strong desire to complete it. But many a times they create problem again and again with more aggressive resurgence. So better let them finish from roots.