I practiced for three weeks exercises from level 1, and got to 100 bpm. Then i got a bit bored, so i had a go with level 2. It was good actually, i only had trouble with timing on the first example when you play 5 notes under one beat. But i sorted that out during next two weeks. I still practiced exercises from level 1, but i spent less time with it than before. My total practice time just on this was around 90 minutes.
To make it harder i played everything on my acoustic, and progress was evident, but after one month of practice i really got bored...

It did not happened all of a sudden...
I wanted to go on but i lacked in
will and
discipline. Those two things are the most important here!
I still practice this though, but not as serious as before, i might get back to it when i "get in a mood" again.