There are many things that I have learned during my mission. I have learned many of these things preparing lessons for district meetings. And they are widely ranged. Scripture knowledge, doctrine, and attribute knowledge. There are many things that are great to know, but the best things to know are those that change our lives, things that we learn and knowing it we change our attitude/behavior/life. I have had many life changing experiences, that aren't the experiences that most people think of when they think about missionaries (baptisms, teaching), but the times when it is hard, when nobody wants to listen to us. Those are the times when I have learned Patience, Diligence, Love, a deeper understanding of the Atonement, and a deeper understanding of myself, and how I can be better in the future. Really a lot of things have helped me understand how I should be later in life, when I have a wife and kids to take care of, that I can help them more than my needs.
I am grateful that God has sent me to hard areas. I am grateful that God gives me strength, because He knows I can do it. I am Grateful for everything God has given me, and all He will give me.