You know...I've always wanted to be the President of the United
States
But that's out of point isn't it?

Ok...you need to remember that he's just your bf at of this moment,
so whatever he chose to work as in the future shouldn't be of any
concern to you now. Reason is simple, you don't own him and neither
does he need your permission to go ahead with his ambitions. So you
shouldn't waste your time concerning about what career choice he
should make, but instead focus more on him as a person and
determine if he is really the one for you. When he's being nice,
concern, caring, sweet...it's really is a standard operating
procedures for him to show his concern for you as his gf. But, does
he make any effort to do things beyond that? You should know if
he's serious about you and the relationship right? 
Let him do what he wants in his life, especially if it is to his
interest. He might excel as an accountant for all you know, so do
keep your faith in him. I don't think he will take a risk and let
you drink porridge everyday for the future. 
Don't think too far ahead when it isn't confirmed that you will be
spending your future with him. Take a break and zoom your visual
back to the present world. It's easier to gain more happiness and
enjoy your relationship if you would just take a step back go with
the pace of your relationship...rather than fast-forwarding it to
preview the anticipated future. 
You can disagree with his decision, but do try to stay within the
fine lines of a concerned gf and not a possessive gf. He is who he
is and you will love him as the person he is to you, never to the
kind of occupation that he's holding.
For now, please make your top priority to strive for a good, happy
and healthy relationship with your bf. For all you know...a lovely
relationship will make him adjust his priorities on his own accord.
So you don't actually need to worry so much about it. As long as
you're getting more and more lovable to him, he will definitely
have to reshuffle/rethink all his present and future decisions for
the sake of not losing you in his world. 
Good luck. 