“There is nothing either good or bad, but thinking makes it so” is a famous quotation of -

“There is nothing either good or bad, but thinking makes it so.”
“There are more things in Heaven and Earth, Horatio, than are dreamt of in your philosophy.”
“Listen to many, speak to a few.”
“To be, or not to be: that is the question.”
“Brevity is the soul of wit.”
― William Shakespear, Hamlet