Most of us believe that it is well worth our valuable time to shore up weak skills- even at the expense of strengthening areas that are energizing and allow us make unique, valuable contributions.
A big reason this mindset is so prevalent is that we desperately want to avoid criticism from colleagues, clients, and (especially) managers. Not many people meet even constructive critiques with smiles, but is working to avoid criticism a better motivator of employee productivity than striving to earn praise? Which is more powerful in engaging your colleagues to do their best?