Brynn,
With mesh gradients it's possible (in fact, very easy) to get mesh nodes that sit on top of other nodes or handles, preventing them from being used. For example, create a rectangle and apply a gradient mesh to the fill. Now switch back to the rectangle tool and try to resize the rectangle using the handles at the top left or bottom right: you'll probably find that the nodes of the mesh get in the way. The only way to get to the resize handles, without moving the nodes, is to turn off their visibility via the buttons on the mesh tool toolbar.
Also, when dealing with objects that have a mesh on both the fill and the stroke, it can sometimes be useful to turn off the nodes for one or the other, in order to more clearly see what's happening, or to move nodes without them accidentally merging with nearby nodes of the other class.
Mark