We may unthinkingly be expecting perfection from our dogs, in the same way we can expect perfection from ourselves. Dogs can have 'off' times too; when they are tired, feel ill, stressed or worried about a change in routine. As a result they may need more space than usual, appear to have forgotten well learnt cues, or have regressed into old behaviours.
Let me give an example of my 10 year old terrier, Beanie. Due to an ongoing medical illness (at the time of writing) her compulsive licking has re-surfaced and become generalised to other areas; it isn't just doors anymore, but kitchen cabinets and blankets too.
It would be easy for me to catastrophise this and take every single lick as a personal failing and insult. Especially as, I believe, our dogs issues can become a mirror of our own. I have repetitive behaviours of my own that I wish I could break out of, which more than likely taps into how I feel about hers.
I adopted Beanie a year ago with the compulsive licking very much ingrained in her. To expect us to have erased that behaviour out of her repertoire completely, in such a comparatively short space of time, would be expecting perfection when none of us are wired that way. She is ill, off her supportive medication, and doing the best she can.
I believe it is wise to routinely look at our expectations of our dogs and check they are realistic and flexible. Our dogs don't need to be perfect anymore than we do.