An elephant encounter can become more interesting when you stop trying to make it closer. From an appropriate viewing position, you can watch how animals move through a setting, use their trunks, feed and respond to one another.
You can visit the Mara during a period associated with the Great Migration and never see a river crossing. The animals may be elsewhere, may remain near a river without crossing, or may move when you are not there.
Rain affects more than whether you need a jacket. It can change the route a guide chooses, the pace of a road transfer, the light for photography and the balance between time outside and time in camp.