If one is aware that one is feeling complacent or self-satisfied about one's practice, a bell should ring out – Danger! Danger!
I say this from personal experience. It has happened in the past, and just recently I felt after a morning meditation that things were truly coming together, there was a coherence among all aspects of my practice. When I said "your will, not mine," I felt a burden being lifted from my shoulders.
And so what happened in rather rapid order? Twice over the course of the following 12 hours I violated key aspects of my daily mantra regarding my relations, my interaction, with others. This caused grief to people dear to me and thus grief to me.
My purpose in life is to offer myself and others joy. When I instead cause someone and myself grief, I am not only not fulfilling my purpose in life, but I am truly hurting myself and others.
And so I must remember what I have said many times: the path never ends. One must be mindful of the power and persistence of one's mind, knowing that if it sees any opportunity, any crack in your force field of spirituality, it will take advantage of that opportunity to assert itself and at least momentarily knock you off your spiritual balance.
My intent is to always empty myself of myself, to be in touch with the Buddha nature/my divinity inside me, the source of my supply, my substance, to be humble before it saying "your will, not mine," and so be filled with abundance and light, peace and equanimity, happiness and contentment, faith and strength, And never allow myself to be complacent.