it's hard for older guys to compete with youthful energy and flexibility on it's own terms.
but it's not just harder, it's *impossible* for a mind that's less dimensionally complex (a youthful mind) to compete with a mind that's more dimensionally complex (a more mature mind) in a situation of chaos and complexity (like the one we are currently in, in other words)
not WHAT we know, but HOW we know, how we see - how we think. higher order intelligence can see problems, opportunities, connections and solutions that are invisible to less complex thinkers. in situations which demand higher order perspectives, it's hard to over-estimate the value of a human who can deliver them.
humans are evolving systems, our minds can continue to evolve higher complexity well into later life. one of the biggest shifts we can undergo typically happens at the mid life point, into (using the model of Dr Robert Kegan) 5th order cognitive complexity.
most of the tearaway successful tech. products of the current moment involve 5th order insight (apple, facebook etc). people who possess the higher order vision to interface IT with reality in radical new ways are unlikely to ever be out of work.
take time to reflect *deeply* on life and reality, do some personal development work (therapy, coaching, meditation, mindfulness exercises). just like building up your body in the gym, if you proactively take responsibility for the health of your own psychology it will grow in complexity and flourish.