hi patricia, gee that's a thought provoking question.

ok i'll take a shot at it...
for me expectations mean that i have a preconceived notion of the outcome. if i have an expectation of another person liking/loving me i am setting myself up for dissapointment because not everyone can live up to my expectation. (of liking me,etc) perhaps they don't even want to, even if they knew what my expectation was!
jme, "dreams, desires, etc." are things i can strive for. i may not get to where i want to "go" but at least i have envisioned that "place" and make efforts to accomplish the journey. if i have an expectation of that dream and fall short, then i will, jme, feel like a failure.
ok here's an example of an expectation i had. i felt that if i was a kind person to others then of course everyone would like me. not so, and i was crushed. my expectation of others was unrealistic. not everyone is going to like me just because i expect them to. there are lots of different people in the world. they all have a value system unique to themselves. it's not bad or good that way, it just is. so i had to rearrange my thinking and acknowledge too that i didn't like everybody else either!!
also many of the expectations that i've had on others i've learned are based on the unrealistic expectations i have on myself. like always being honest, always being kind to others, be the very best of the group (like school grades), always understanding of others, always helping others, ad nauseum. no one can be everything to all people. it's too big of a job! i had to learn to accept myself with my own imperfections (cause i fall short of the above also.) that was not easy and comes back to bite me in the xxx sometimes even now.
now how'd i do? as usual i want to have given you a "good" answer cause i expect that of myself. hummmm.

but i must humbly admit i may have fallen short.
the only difference today is that i can accept that, if that is the case and your perception of my answer. course i wanta be "right" but there's no real definition of "right" in this context, so there you go....