Network envy is a common malady among network managers. If your network users are humming along fine at 100 Mbps, don't covet your neighbor's 1000 Mbps network. If your network users are happy with Windows XP, resist the urge to upgrade to Vista unless you have a really good reason. And if you run Windows Server 2003 Server, fantasizing about Windows Server 2007 is a venial sin.
You're especially susceptible to network envy if you're a gadget freak. There's always a better switch to be had or some fancy network-protocol gizmo to lust after. Don't give in to these base urges! Resist the devil, and he will flee!