Expectations

What is it to have "Expectations" Does it mean we expect something will happen in now or the near future......
Like i may have Expectations in you or you may have expectations in me...

As Donald miller said

“When you stop expecting people to be perfect, you can like them for who they are.” 

I think for me i expect people to be there for me when i cant be there for them or i expect people to treat me Differently when i wont do the same...

Thats been  problem as someone who Expects differently from people and to be treated differently...

Another great quote from Lisa Kleypas States that

“You are your own worst enemy. If you can learn to stop expecting impossible perfection, in yourself and others, you may find the happiness that has always eluded you.”