it's very short! Could you help me?

Overall speaking, peer pressure is an inevitable part in young people’s normal  of a young persons life, but in fast growing cities, this phenomenon is more serious. To solve this problems problem, governments and individuals should work together.

Parents within 30 years will be even worse than us.

The role of men and women have been developing since the ‘90s.
If we look back on the past we can see how our mothers and fathers’ roles were as different than ours are nowadays. For example, a regular night in the past, our mothers made dinner, bathed us and took us to bed while our fathers were lying on the couch watching a football match or just idling their lives away. And what did they do during a typical day? I am sure that all our fathers worked out  outside of the homefor all day long during the day while our mothers did all the cleaning, went shopping, made lunch, picked up the children from school and our mother was who raised us.

Gradually those roles have been exchanged today.
Every day there are more and more parents who work out during all day long and in most of those cases, grandparents are in charge of taking care of their grandchildren and parents have to share their chores at nights without time to spend with their children.

Then, who will be responsible for the children in 30 years’ time? obviously us. We will be who look after our children’s children as they will work as we are doing now. The fish that bites its own tail.

Good job. That is very true where I live I believe. 

The notion of time

All days have 24 hours, 1440 minutes and 86400 seconds. Every day has the same time, each day is exactly like some the  other, but sometimes, this is not our sensation perception. 

One day it's Friday and suddenly it's Monday. What happened to Saturday and Sunday? What was up? The answer is that you are happy
The Time flies when we are spending having a good time with the relatives, friends or partner. When we go to see an amazing show, film or performance or when we are reading an awesome best-selling book. Time flies too when we are on holidays because we are having fun.

Nevertheless, another day it's four o'clock and much later it's four fifteen. What happened? What's up with the  your watch?? Is it broken? No, the answer is that you are unhappy.
The time drags when we are bored, worried or sick. When we are waiting for, someone or something, or when we are cleaning, ironing or doing the homework.

I cannot understand the reason for why it mostly happens this way. It would not be better than the time drags when we are happy and that the time flies when we are sad, worried or sick?. This world is upside down

Good job that was interesting. You can also contract these words but either way is correct. The contracted version is more commonly used. 

Cannot - Can't 

Would not - Wouldn't 

Here its used as a reflexive pronoun. Here is some examples: Itself is a reflexive pronoun, being the reflexive form of it. It can be used especially in the following ways: as an object that refers to the same thing that is the subject of the sentence or that was mentioned earlier in the sentence: The machine turns itself off when it has finished printing. The civil war divided the country against itself. after a singular noun or pronoun for emphasis: The document itself is divided into three parts. That itself is the problem.