sure! i'm a lawyer, and when i was actively listed for transplant i was still working full time at a major wall street law firm. i did take disability to wait for lungs and get the transplant, and i'm still not sure when (or if) i'll go back to my former job -- but i know i want to go back and do something when i'm able!
by the time i was in college i was going into the hospital at least twice a year, and doing plenty of oral and inhaled abx. law school was slightly worse, and believe me i took plenty of time off during my job. but i don't regret a single instant of any of it. for one thing, working was FUN and gave me a sense of myself outside of CF. for another, it's practical - you get money and health insurance, and a good job will often offer disability benefits if/when you do need them. win-win situation, if you ask me.
obviously everyone's different. i'm on disability now, so of course i understand that sometimes you just can't have a job. but i really strongly encourage you to pursue your interests, whether through a job, volunteer work (which you can always leave for hospitalizations), or school. these are social activities and they really help keep CF from becoming your whole life in my experience. do as much or as little as you can honestly handle, but do what you love. and be extremely proud of yourself every second of it!