I would like to learn how to use better English expressions(27)

Valuable experiences!. This is what adults always counselled.  say that we can’t replace any Nothing can take place of experience we’ve gained from life with anything else. After going through this incident, I felt as if I had matured greatly.  become more mature. [Nothing wrong with what you wrote.] Tempus fugit! Time flies so fast. [Again, nothing wrong except for the tense] It seemed that I kept myself busy with my studies and works. Not even I got a girlfriend to have. This is why I didn’t have time to think of this the friend.

I would like to learn how to use better English expressions, so I hope you can help correct errors in my writing.

What a coincidence, I was just writing on time too :)

I would like to learn how to use better English expressions(27)

Valuable experiences. Adults always say that experience gained from life can't be replaced with anything else. After going through this incident, I felt as if I became more mature. Time flew so fast (1). It seemed that I kept myself busy with my studies and works. I even got a girlfriend. This is why I didn’t have time to think of the friend (2).

I would like to learn how to use better English expressions, so I hope you can help correct errors in my writing.

1). Where I come from we say multiple things for this phrase. The one that sounds most natural to me is: Time flew.(Nothing else just those two words) Another one that is used more when speaking is: Oh, how time flies. 

2). It is a little confusing as to why you put the in front of friend. Did you mean "my friend", because otherwise it sounds like you are foreshadowing a future event.

If you have any questions feel free to ask!