A kid is generally known to always complain when they do not get what they want or when things don't go their way
Some of them in school loose their happiness when they do not meet a certain position, especially the brilliant ones. The start blaming the teacher for their failures and all that
Some raise allegations that they teacher favored others over them and hates their success.
The worst case scenario of these complaints is when these ones carry this nature in growth.
This gives a feeling of 'it's not my fault', and responsibilities are avoided.
There is no better maturity than comes in life than that of responsibility.
Proverbs. 24:10
"if you faint(fail, fall, lose, etc) in the days of adversity(pressure, challenges, exam, etc), it is because your strength(capacity, storage, qualities, treasures, knowledge, etc) is small"_
This shows that whatever challenge we face is as a result of our inadequacy in an action or an area of our life. Let me explain further
If a devil sees a child of God and flees and then sees you and torments you, is it not an indication of a problem?
If we give ourselves unto capacity development, we will discover how much strength we posses and when this strength is utilized properly, there won't be any need to complain.
So my advice for any setback or challenge is, GO AND BE BETTER._ I hope you catch my drift.
Read Acts. 19:20
I admonish us to quit wailing, crying and sulking when we fail or are faced with challenges. Instead, go and develop yourself and be a better individual. You obviously will prevail and win.
Change your attitude.
Take responsibility.