With all the high-tech and fancy materials in boots nowadays, I was wondering how long they last after production before they start breaking down or degrading. If a new boot sits on the shelf at a retailer for say 2 years, will it be in any worse shape than one that just comes off the production line (design changes aside)? In other words, should you avoid boots that have sat around in the store for some time? Does it make a difference if they are leather or synthetic? Can you really hoard boots and expect that they will perform the way they should in a few years' time?