I write in a gratitude journal every morning! It is nice to see someone else engaging in a similar practice!
And you are right. Humans have a lot of difficulty being grateful. We are constantly craving more of something.
Taking a moment to stop and experience gratitude is important. I hear you when you say that you worry about sounding "trite", but you are actually being quite wise when you see the value in gratitude.
Writing in a gratitude journal seems like such a lovely practice. I should make it one of my new year's resolutions to start one!