Finding joy is simple and inherent. In most cases, people spend way too much time outside of themselves feeling a feeling caused by someone else or something else. You feel what you want to based on what you give permission to in your life. Your spouse doesn't take the garbage out, you get mad. Someone swears at you in front of your children for no reason, you feel confused and hurt.
It really takes looking at yourself first and foremost in all these instances. WHY does this event or person make you feel this way? Introspect to find out who you are. Once you find out who you are and are comfortable within yourself you will have the ability to be unaffected by other people in a negative way. You can see right through their actions and words. Focus on you, not outside sources. We are told who to be and what to believe from the time we are born. We will NEVER measure up. Sometimes finding joy is as simple as loving yourself.
The last person people choose to show love to is their Self. They put everyone else first. Loving yourself isn't selfish or vain, it's truly understanding that you can not truly love another person until you recognize and love yourself for who you are. Once you do that you can find joy in everything. You can see the beauty in painful situations.