Stress is what you make of it - it is merely in the eye of the beholder.
I can honestly say I have NEVER been stressed in the "classical" sense (aggravation, depression, agitation etc). As others said, hard working, and sometimes flabergasted, but never stressed.
I find, like Old Smokey, the "normal" world more of a chore than the relief of flying, be it BAD weather (adrenalin, and makes you THINK more ahead of the aircraft) or fine weather. In Flight situations do NOT call for stress, they call for a calm, inquiring mind firing on all synapses, not some dimwhit flathead panicing and snapping at every siuggestion.
Stress is a state of mental "agitation", whereas boredom is a state of excessive mental relaxation. BOTH are killers, but people handle each mental state in different ways.
Anyway, the most "stressed" I have ever been is for my Australian ATPL examination - as usual in my training, I had not studied except for the last day before the exam. 8 hours of questions ahead, and my mind was FULL of facts, figures, law, met, performance, and nav. I was a little tremulous upon sitting down - my mind was racing to facts and figures, and "What am I going to do if I fail - I don't want to do this again".
The first paper was put in front of me, and the examiner announced to open the paper. Looked down, said to self "THINK, and READ THE F&^KING QUESTION!". Instantly relaxed, and proceeded to churn out answers....
Needless to say, I passed first time around, with an overall mark of 94%!!!!!!!!!!!!! ( I got LESS on my IREX!)
I never was "stressed", more overly concerned.