The large charge approach allows to describe special sectors of strongly-coupled systems. When another controlling parameter is present, it is still useful because it allows to unveil interesting mathematical structures and access previously unexplored parts of the spectrum. In this talk I will concentrate on the O(N) vector model in the large-N limit, give a geometrical interpretation of the asymptotic expansion of the dimension of the lowest operator of fixed charge, and use resurgence to resum this expansion. The result suggests a still unexplored interplay between conformal symmetry and resurgence and will lead to an intuitive interpretation for the impressive agreement of the large-charge predictions with lattice data also in the O(2) model case.