I think its because there is no challenge when you get used to it. No new ideas. Which isn't bad, that is a challenge in and of itself. But yes, after 6 months I do want to change it up. I miss painting I have no paints right now sadly.  

 Why not paint? 

I do watercolors but rarely acrylics, Watercolor is somewhere between drawing and painting. Mine is more drawing, 

I see people  drawing with acrylic paints on the sketchbook or a big paper.  

 Just not a good time. I have limited space and materials at the moment. 

 I do have a limited space too. Totally.