I just stumbled upon this little poster below. I must say this is utterly wrong. Let me explain why.
Big disappointments do not come from high expectations.
Big disappointments do come from your own poor performance. Get acquainted to that truth. Stop searching for excuses.
High expectations are the best you can have. High expectations let you long for more. High expectations let you learn, train, evolve, develop.
High expectations let you stretch. High expectations let you grow. High expectations let you outgrow yourself. High expectations let you become a better person, friend, colleague, boss.
You should live a life of high expectations. You should accept nothing less. From yourself and others.
High expectations conquer the average.
Get rid of the averages surrounding yourself. Become a role model of high expectations and high performance.
Raise the bar, continuously.
Excel yourself - if nobody else does!
(And - just in case you are focussing on expectations vs movies, music, sport teams et al. now - by living the above you will learn, and get better at, forecasting the true quality of (passive) (third party) entertainment.)