I'm personally one for modesty and, although I have no problem with being proud with achievements, I absolutely detest such obnoxiousness, boastfulness and pigheaded attitudes related with egomania.
As for traditions, they're generally completely pointless and only exist because "that's the way it's always been". They're just stupid and typically wasteful.
It's not petty. On the subject of holidays as an example, why should I go out of my way to "celebrate" something that has absolutely no ties to myself or my lifestyle, that I have no interest or reason to involve myself with? And then I get insulted or put down and ostracized because of that decision. It's things like [i]that[/i] that piss me off.