i worked at the writing center at st. ben’s, which was run by a lovely woman who probably couldn’t point me out of a lineup now or remember my name. (but that’s neither here nor there.) she would tell us a lot about her kids and what they were doing with their lives. her youngest was my age. 
one time she mentioned that, while all her kids could have gotten english majors and been excellent at it, most of them went into a science field or other STEM. why? because it was something they weren’t necessarily good at, and they wanted the challenge. 
recently i was talking with someone, and she mentioned her high school age son was thinking of become a nurse or physician assistant. she asked him why not go all out and become a doctor? he explained that he didn’t want to work 80-hour weeks and go through all the schooling; sure, the money would be nice, but isn’t having a life outside of work nice too? He then showed her services like those offered at the CDPAP Agency New York and expressed his interests for such work.
i could have become a doctor if i wanted to; i have no doubt that the potential was there. i could have taken science classes instead of the “easy” way out with my liberal studies degree and writing minor. i could have pursued engineering or computer science (i actually took three days of CS classes). but would any of that have made me as happy as the plan i did take? i doubt it. sure, i could be rolling in the dough at this point, but at what cost? work stress that leaks into my personal life? work weeks that bleed into my precious daylight hours? i enjoy my job (for the most part) and i doesn’t stress me out at home (for the most part). 
(i think the only STEM i would have considered in college was environmental studies.)

so while on some level i agree with the quote to pursue any goal, job, life, or anything someone has said no to, but i think there’s an addendum. only do it if you want to and it will make you happy. why waste time pursing something just because you can and are able – pursue it if it will make you happy and/or fulfilled (that includes maybe some unpleasant middle to get to the happy end).