When I was in my 30's and just out of graduate school with my new PhD, there was no question that flying to remote observatories and spending a week getting data that I had planned to get the year before, was the most exciting part...that plus going to professional conferences to present papers about my research. I even traveled to Holland and Italy a couple of times. The experience of discovery was pretty neat, but I never really made any world- famous discoveries, so I never had the thrill of getting that type of recognition.
Now that I am in my 40's and have two daughters in pre-school and Kindergarten, I detest traveling and avoid flying as much as possible to avoid checking out of life in an accident. Still, I am scheduled for 3 trips this year to conferences on education that I am trying to get out of. As for research, I am now into some exciting new areas that might end up uncovering some exciting new things about the conditions in the early history of the universe. I am also back into teaching adult education courses in cosmology, and these give me a tremendous amount of satisfaction.
The bottom line is that when I am teaching, I am always at my happiest and in a state of the greatest professional pleasure. Research itself can be tedious and at times un-rewarding for the effort made. Teaching for me, on the other hand, has never been tedious or frustrating or a task to be dreaded.