There are many unanswered questions here. Were you given feedback throughout your orientation period, or were you just told one day after 4 months that you were unacceptable? Did you show interest in what was being taught? Did you show initiative? Were you receptive to learning? Were you assigned a preceptor/mentor? Did you communicate with that person? What is your personality type - outgoing or introverted and shy? I think now is the time to step back and be real honest with yourself. Answer questions such as: what did I contribute? what did I learn? was I open to learning? was I an asset to the unit? Did I act like a know -it-all? Did I receive (did I listen)? was I able to retain what I was taught?, etc. The list goes on. Were the unit expections made clear to you? Did you receive the proper education for your job? As far as what to say to those who want to know why you left ICU- a simple "ICU did not work out for me at this time, period"