Though, like many others I am drawn moth like to the entrancing flame of polymathy I am aware of the many pitfalls associated with too great a celebration of polymathy. First, the word itself is a bit of a mouthful, but that aside, the real heart of it is that polymathy is a pretty slippery concept. I have defined it elsewhere as demonstrable expertise in three or more areas covering the wide terrain between what is generally thought of as art, science and practical/physical skills. It isn't just about being a head person, you need to have some body skill or manual skill too. Not for nothing did the old rulers of turkey insist that the king have a real trade such as carpenter, carpet weaver or mosaic maker. Professor Richard Gombrich once suggested I train as a plumber whilst writing poetry- and I probably should have done it!
Polymathy is slippery, but practical polymathy less so. I think of being a 'practical polymath' as a pretty good identity and 'party hat' to wear. You go to a cocktail party or some other gathering of humanoids in search of oblivion/company and tell people you are a polymath- they read this is a 'bit of a wanker'. But say you are a 'practical polymath' and things might progress in a more interesting direction. I hold there is no point in revealing yur profession/identity unless something fun/useful/interesting comes of it. Better to get a laugh by saying you are a pig rustler than the sorry silence that accomapnies a real admission of one's trade. In italy people feel Ok being introduced by their chosen identity- thus a cloth salesman can be 'the poet' and a dustman can be 'the philosopher'. brits and yanks are more lieral minded, poor souls, so craft yor identity well, make sure it works.
Practical polymathy is about acquiring micromasteries. That is, small, definable lumps of skill that can't be taken away from you. It is also about recalibrating what you know in terms of micromasteries. Thinking of it in this way. It is then about using the synergy that occurs when you have moe than one micromastery.