cant be difference to the center word like both side
can I ask what is the problem with it? is it because there is a tiny scratch part to other part (hmmm poor english hahaha , so sorry, I hope you guys understand , thx 
do you mean, the curve not closed yet? so I have self connecting curves end to end? then blend curves?
self intersecting mean?
thx Mr. Sochin 
Your curve is closed but it overlaps itself right near where the gumball is in the photo. Explode the curve and you will see.
When you create objects using curves that overlap themselves you get surfaces that over lap themselves and then boolean functions fail.
If you created that curve from a system font then from my experience you should expect these sorts of problems.
Wow… its great now ^^
big explode in my mind too
Thx Mr. Sochin for your big Help
Salute