Same reason why people take selfies. I'm not sure what that reason is, I only know it's the same.

That's great that you want to blog to improve your language skills. I definitely recommend it!

I think everyone has a different reason for blogging. Some people have interests and knowledge that they want to share with others. An example I can think of are lifestyle blogs or fashion blogs. 

I also know people who simply want to document their lives (especially if they are experiencing something special, like studying abroad). And they don't mind strangers reading the things they wrote.

I have forgot to write - I never take selfies) However I want blogging. I know it doesn't mutter, just for information)

People are lonely and strangers in this time,.they need warm friends and lot of people to share they private life because they don't know are they exist in this world

It is an interesting thought that blogs and selfies have something similar. I have never match these two actions before. However I think, you are right, aegis. There are something common between blogs and selfies.
I suppose that Oskar thinks people write blogs to ask an objective opinion or advice. Maybe. Partly I agree with you, although it is not about me. It would be very interesting for me to know stranger's opinion, but I trust my family best of all. Any way I appreciate your view of the situation, without the favoritism)
And thank you, overbyen, for your support and encouraging me to write blog. I am really going to do it as soon as possible. Unfortunately it is impossible now because of lack of my time.
I would like to add that what I know exactly, I really don't want to write blog on my native language. So I assume that my authentic target is learning foreign language. In this way I would make my learning more entertaining.