Sometimes we expect too much from ourselves, our performance or even from other people. Sometimes - it is the differential between the desired outcomes or behaviours and the actual outcomes or behaviours that causes us stress or concern.
In terms of our own performance, it is easy to 'expect' too much. On one hand, if we set the bar to low, we are cultivating with ourselves an acceptance of mediocrity - if we always set the bar too high, we are setting ourselves up for failure. My own view is that we should set the bar high, but not overly concern ourselves with the outcome - that way we move beyond mediocrity but don't find ourselves always paying the emotional price for failing.
When it comes to what we expect from others, in terms of performance - or even just in terms of how we expect people to behave or to act - it is even easier to set ourselves up for disappointment. This is largely because we think others will think and behave like we do, have the moral standards as we do - and we tend to forget that people are, as the saying goes, 'queer as folk'.
Other people will behave, perform and act in accordance with their own set of values and from within their own particular world-views. Oft times, those values and those world views do not match our own. This can cause problems, but only if we have unrealistic expectations of how people should perform, behave and act. But hey, sometimes, it may just be that they have 'other stuff' going on in their lives and their behaviour or performance, although hypocritical, sub-par or not in alignment with our own, may just be a temporary thing - fueled by an unfortunate series of events or feelings that they are experiencing. As a friend of mine used to say 'They are who they are - don't expect more and you won't be disappointed'. Sage advice.
It is also important to note, both for the individual and for the professional coach - that everyone has ups and downs in their lives and in their training. The longer the relationship (and the stronger the relationship) between friends, or between coach and student, the more 'friendship or relationship credits' should be available to get over the 'hump'.
I see people dealing with these issues all the time - in their personal lives and on the mat. Having unrealistic expectations about our own performance can send us spiraling into a state of unease; having unrealistic expectations of our we think others should behave and act can casue us heart-ache and sorrow.
My advice - cultivate tolerance - for ourselves and for others. People after all (including ourselves) are only human.