Somehow you can make head and tale of written Japanese.  Given the time you can construct decent Japanese sentences on your computer or make yourself understood one to one.

Why is it then that you're left high and dry when two Japanese people talk to each other?  Why is it that you still need subtitles for Japanese movies? 

Why is it, after all this time, you still don't always get what Japanese speakers say, dammit?!

Just when you think you've gotten the language down pat, your listening comprehension still pulls the rug out from under you, doesn't it.

Okay everyone, roll up your sleeves, because improving your Japanese listening comprehension is a biggie. 

That said, don't get too serious about it. The solutions are simple but involve a paradigm shift.

My take on the secrets to understanding spoken Japanese are: 

• learning to mimic a Japanese person's speech; and
• increasing your vocabulary