They say "you can not serve two masters at the same time"...

I totally agree that it's hard to do so.... but "the can't" is but a relative word.

It is not totally impossible to do both if you have the passion and determination.

Though, I often wonder how life would be less complicated, not to mention stressful, should I only be studying and not working at the same time.  

I know and I imagine how much time I could devout then to my second course and the probability of excelling all the more in the later field.  

However, I could not forgo the perks which i I also enjoy "with being employed".  Such that as a working student, monthly salary has been serving as the means of subsidizing my studies and sustaining the lifestyle that I have.

It is hard to juggle everything, but I must admit that it makes the journey not only challenging...but fulfilling as well.