The Bodhisattva vow is to awaken with all beings realising the impermanence interdependence and perfection of all life. From our deep realisation of this reality arises deep compassion and gratitude. The realisation that we and life are perfect just as we are is hard to understand. We think, this doesn’t feel like Buddha, because we have expectations or beliefs about what we think Buddha should be like. We habitually resist being just this moment. Please observe this.
Gratitude can be taken up as a practice in itself, both formally and/or informally, which is perfectly in harmony with Zen practice.