the two point correlator of an operator with a bare dimension $\Delta$ of most $\Delta\sim J$ with ${J^2\over N}\ll 1$, then summing the planar diagrams will capture the large $N$ limit. For operators with a dimension larger than this, exploding combinatoric factors overpower the nonplanar (${1\over N^2}$) suppression and the planar approximation is completely ineffective[@Balasubramanian:2001nh]. In this scenario, to get the correct large $N$ limit, it is necessary to sum a lot more than just the planar diagrams. On general grounds we expect the large $N$ limit to be simpler than the full theory[@'tHooft:1973jz]. The planar diagrams are a small subset of all possible diagrams, so that it is quite natural to expect that summing only the planar diagrams will give a much simpler problem. Why should the large $N$ limit be simple when one needs to sum much more than just the planar diagrams? The answer to this question will probably not be general, but rather will depend on the specific dynamical problem considered and must be answered case by case. A very pedestrian approach is simply to compute the large $N$ limit and then to look for simplifications. This has been accomplished[@Koch:2008ah; @Koch:2008cm; @Koch:2009jc] in a number of 