It is only natural that newer players feel a huge sense of accomplishment when they beat someone who they idolized. That being said, as you stated, winning one game against someone does not serve as an ultimatum that you are better then them. There is a lot more then just skill that goes inside one pokemon match. Sometimes your opponent could have a slight matchup advantage which would mean that you would have to win more 50/50s. Rarely are there ever matchups where both sides are exactly evenly matched. Even in mirror matchups (where both people have the same teams) there are 50/50s and things the players cannot control like critical hits or secondary effects from moves (such as burn from scald or flinch from iron head). The only hax that can be controlled are the moves that people teach their pokemon; even so, there are moves like stone edge and playrough which are not 100% accurate and do not have viable alternatives to them. In essence, unless you beat someone consistently, there is no point in gloating about one, two, or even three wins.