Is the intention of reincarnation that we become adept at all things, or are we meant to specialize?

The universal law of evolution is away from uniformity and towards diversification. Therefore we are not intended to become ‘jacks of all trades and masters of none’, but are meant to develop along specialized lines. Reincarnation does not mean a universality of common experience; it means a concentration of experiences towards a certain end and these accord with the drive towards the development of individuality.