Learn to let go,is one of the chapter we should learn in life

As i growing up,i started to realise that people tend to enter and leave from my life unexpectedly,relatives,lover,friends or even pets.I am not only mean death and live,but also those who are important to me,living their own life without involving me.
22 years of living in this world,i expect myself can cope with this real life "tragedy".I called it as "tragedy" because it is devastating when someone who is not a passer-by,but someone who is a piece of your life started to walk out from your life.That doesn't feel good...It seems that i am over expect my ability to cope with these tragedies when they come to me together.I still have a lot to learn,i've just learnt part of the chapter.
Maybe my grandfather really gave me a huge impact on my emotions after he leave this year,he was leaving to another world.A world where i hope full of happiness and peaceful,a world where he love to stay and waiting us to meet him,someday...I have these several important man in my life,but he is the most important,no one can beat him.He is the best man i've ever met,taking care of his grandchildren like a father does.Always called us to go back his house,because he missed us so much,wanted to see us.For him,nothing can be more important than families.When things not going well,he dropped his tears silently when nobody noticed,but my sister saw it,accidentally...He suffered too much before he'd leave from this world.Tears rolling in my eyes whenever i think of him.Miss him too much.But i should learn to let go and move on.
Now,another man is leaving...he is leaving from my life to live his own.Although he did not mention,or even not realising it,but his actions already proved that he is leaving slowly,from my life.That is why i choosed to give up before thing gets worse.At least i apply what i learnt from secondary,"to let it go..."
Each time when i saw ah gal,my doggy,my heart sunked again and again.She is getting older and older,walking slower and slower.She can hardly run now,she can't see anything either,that's why she wont walk any far if nobody besides her,she needs me,she needs us.I can't imagine the day she leave me...