My drawing

[multioscar]

Quite terrible..... Isnt it?
In this picture, I use pen tool to create.
But, everytime I want to fill it, it just doesnt work. I have already zoom in to check but cant find any gap . This picture has only 1 layer.

Can anyone give some hint?

[tayjax]

you can also go to the fill options on the left and select close large gaps that should deal with any little gap you've missed

[multioscar]

I got it thanks