[nitrogen]

If one was really being mindful

There's a sort of No True Scotsman fallacy combined with confirmation bias that comes into play with other spiritual practices with which I am experienced. For example, "If your prayers aren't getting answered, you aren't fasting enough and praying hard enough, or you are praying for the wrong thing."

This is an easy trap to fall into with anything that generally works for some people but not others, and it's important to remember that there are other dimensions beside "really" or "enough", plus general randomness, that affect whether a practice/belief/etc is good for a person and successful.