If a knight gained spoils of war through his prowess, does not a lavish gift to a lord say (to everyone, not just the lord), "Look at what I can do! I'm a big deal!" At that pont, as knights try to outgift each other, is really about currying favor with the lord, or about being better than the other guy? Granted, the one with the best gifts was probably granted favor, but would a lord give more and more power, wealth, and responsibility to someone who couldn't back it up?
Very true. Many knights would have been the ultimate jocks of their day. Competition and rivalries would have been commonplace, and knights certainly would have been looking for opportunities to test their mettle, prove their prowess, and build a reputation as such. Tournaments were as much about these things as staying in practice, winning awards, or just having fun (or having an excuse to beat up on someone).