Joe Thorn writes
In fact, your complaining about the small stuff is more dangerous than complaining about the big, because life is made up of the small stuff. Tragedies punctuate periods of your life, but it is the smaller inconveniences that make up the bulk of your existence, and this is what most people will see you handle. Those situations are the most obvious testing ground of your faith. If God’s grace is big enough for you to handle the big problems, why isn’t it enough for you to walk meekly though the smaller issues? (As quoted in Gospel Gripped by Matt Perry. Thanks guys!)
If this is you as it is so often me, let's repent of our complaining and start focusing on the Gospel, eh?