I started smoking more (due to stress) and trying to complete a new project (financial difficulty) and it was just a nightmare.
It's noticeably more difficult to concentrate and retain new information when I am ingesting regularly.
Learning a new programming language, even having just had a few joints the night before, is so much more difficult that it would be without the Cannabis. I honestly felt like I was losing my mind.
I'm not even talking about being high while learning/working... just having the cannabinoids in your system from a few days ago really soaks and coats the mind.
So I've cut it out, for now.