Why do people always want the latest and greatest

I'm one of those who immediately reaches for my credit card when an upgrade to a specific "man-toy" consumer item is announced…even if I already own the most recent version; which by the way, met my needs perfectly the day before the upgrade announcement was made. Items which act as a magnet on my wallet include camera gear, computers, iPods, and lastly, fishing/kayaking gear. Years ago, I wanted every new golf club and light-weight bag that came on the market, and the last time I counted, I had more unused putters in our garage than I did golf clubs. It's one thing to replace a still adequate and fairly new item costing a hundred bucks or so, but another when the item cost approaches the one thousand dollar mark. Cost aside, my heart literally pounds when I see, for example, a new Nikon camera, or Apple computer that has all the latest and greatest capabilities people like me covet. Thankfully, as I've grown older (and more frugal in my spending habits) I've been able to keep my pent up desire for all things new well under control. However, I still spend a lot of time dreaming how better off I'd be if I had that new item in my hands.