Most Helpful Guy
Solomon said it better than I ever could, in Ecclesiastes, and I don't know the Bible well but I love this part:
"And I gave my heart to seek and search out by wisdom concerning all things that are done under heaven: this sore travail hath God given to the sons of man to be exercised therewith. I have seen all the works that are done under the sun; and, behold, all is vanity and vexation of spirit. That which is crooked cannot be made straight: and that which is wanting cannot be numbered.
"I communed with mine own heart, saying, Lo, I am come to great estate, and have gotten more wisdom than all they that have been before me in Jerusalem: yea, my heart had great experience of wisdom and knowledge. And I gave my heart to know wisdom, and to know madness and folly: I perceived that this also is vexation of spirit. For in much wisdom is much grief: and he that increaseth knowledge increaseth sorrow."
The only (apparently) truly happy people I have known had not much wisdom or knowledge. And I felt something close to envy.
Most Helpful Girl
Everyone has good days and bad. The key is to focus on the good and try to be grateful for hat we do have as opposed to what we don't.
It's a bit harder if you're dealing with mental health issues though... if you're in that position try therapy and/or medication.