ya man, I had been a regular smoker for over 12 years 

then 3-4 years ago I started jiu jitsu and had to make the choice between the two 

of course I chose the art of folding clothes with people still in them.

But to your point quitting made me soooo focused and felt like I gained all this extra time.

PS. I did hit it few times in the last 3-4 years and had a boost of creativity 

but I don't think I'll ever go back to be a regular toker