An under-appreciated factor

I am not an ecologist, but everything in my lab starts in the field. It may be a small portion of the overall project, but is nevertheless essential. Because of this aspect, trips into the field are a common feature of what I do and I am just about to complete the first such trip as a faculty member, directing all of the details of a week-long quest to find very specific things in the wild. Everything worked out better than I had hoped and we should be working with the fruits of our labor for a while now.
One thing I did not really consider before the trip, however, was the impact that the student I brought with me could have on the whole week. Having been on many such trips before, I have had experiences at all points on the spectrum, from unmitigated disaster to unbridled success. For some reason I never attributed the differences specifically to the people on the trip, perhaps because they were always a complex mix of personalities who were my peers. As an advisor and planner of this trip, I have a very different perspective.
I can not understate how important it is, at least in the early stages, to have people to travel with who you are happy to spend time with. In the last 5 days I have pretty much spent every waking minute with the grad student who came along with me, in a variety of situations. Amazingly, we had a great time, had plenty to talk about and never spent awkward minutes between forced conversation. That alone made the trip infinitely more enjoyable and easy. I don't think it will be the lead criterion for selecting students in the future, but I also underestimated how important it can be. The long hours we put in are hard enough without having to look forward to time alone.