It's about how you handle the stress and pressure in any job.
Anyway, I was a purser too, thoroughly loved it but to answer the original question and for everyone who is/was a purser then the reasons why you enter into that role aren't the same as everyone elses. Make sense? I entered into that role because the opportunity was there, I felt I was ready for it and I wanted to expand my knowledge that bit further and I wanted a challenge. It changed me somewhat, for the better and opened my eyes that bit wider.
Differences? Once the doors are closed, you're in charge and if it all hits the fan, well you have that big responsibility. I had 2 aborted take-offs in my career and when the aircraft stopped, it really dawned on me when all the pax looked to me to see what to do. Luckily everything was fine but I put that down to experience and a great team, including the flt deck.