It can be a useful exercise. My first camera when I was 12 had only a 75-150mm zoom lens, and I think it was responsible for teaching me to choose and capture a subject, rather than just shooting the scene with a wide angle...
A very nice photo journal of your trip. The Canon 50mm 1.8 is certainly one of, if not the cheapest, lenses Canon makes, but it is a great lens, especially for Astrophotography.
When I bought my expensive Nikon D700 body I had no more money left for a good zoom. Therefore I used my Nikkor 50mm 1.4 D from my analog time for quite a long span of time. It kept me busy to walk around to find the best place to shoot.
Working with the 50mm lens only, requires a lot more careful positioning, and as you say you probably missed opportunities. But I was surprised how close you could get to the animals just with the 50mm. Next time when you go, take a super-zoom point and shoot camera as well. Small and relatively cheap. You'll be surprised at the results especially those in good light.
I wish I could go...
Long before there were zoom lenses, photographers got along fine with just the "normal" lens and maybe one other. The biggest problem of only having the 50mm lense would be getting those close-ups of poisonous snakes, large spiders, etc. I'm guessing the colobus monkey was cooperative.....
prime lenses remind of the time when all I had was a Minolta Hi-Matic 7sII. I never had a problem with that camera so I guess getting used too much with zoom lenses may cause some discomfort when forced to use only a single focal length. But it never really does become a big problem.
Limitation makes you get creative - you've proven that :) Anyway, I think you did the right thing. If I would go on that trip and had to take only one lens with me, I would take my 2.8/90 macro.
Nikon D700 with Nikkor's, Nikon 90x, Leica X2, Canon S100
