The only way to ever become truly happy is to trustfully surrender oneself to God’s will. If we make the decision to perfectly unite our wills to God’s will, it will be impossible for anything displeasing to happen to us.
But the second we make that decision, we will be tried. God will test us to see the degree of our resolve. If we decide to accept everything as coming from the good hand of God, He will inevitably send us things which appear to be bad. We will suffer contradictions, and we will bear crosses. God will make us prove ourselves.
The wise man should expect and accept such dealings, and he should see them for what they really are. Nothing can ever change the undeniable fact that everything that happens to us is good. No matter how disguised that good may be, it still all comes from our infinitely good and heavenly Father.
So make the decision to be happy by perfectly uniting to the will of God. And then prepare to be tried. Persevere, and eternal happiness awaits.