Genesis 40 -- Joseph Interprets Dreams

Genesis 40:1 After this, the Egyptian king’s cupbearer and baker offended their master, the king of Egypt. 2 Pharaoh was angry with his two officers, the chief cupbearer and the chief baker,3 and put them in custody in the house of the captain of the guard in the prison where Joseph was confined. 4 The captain of the guard assigned Joseph to them, and he became their personal attendant. And they were in custody for some time.
5 The Egyptian king’s cupbearer and baker, who were confined in the prison, each had a dream. Both had a dream on the same night, and each dream had its own meaning. 6 When Joseph came to them in the morning, he saw that they looked distraught. 7 So he asked Pharaoh’s officers who were in custody with him in his master’s house, “Why do you look so sad today?”
8 “We had dreams,” they said to him, “but there is no one to interpret them.”
Then Joseph said to them, “Don’t interpretations belong to God? Tell me your dreams.”

God is the creator of dreams and the interpreter.  God used Joseph to interpret the dreams of the who officials. 

Genesis 40:9 So the chief cupbearer told his dream to Joseph: “In my dream there was a vine in front of me. 10 On the vine were three branches. As soon as it budded, its blossoms came out and its clusters ripened into grapes. 11 Pharaoh’s cup was in my hand, and I took the grapes, squeezed them into Pharaoh’s cup, and placed the cup in Pharaoh’s hand.”
12 “This is its interpretation,” Joseph said to him. “The three branches are three days. 13 In just three days Pharaoh will lift up your head and restore you to your position. You will put Pharaoh’s cup in his hand the way you used to when you were his cupbearer. 14 But when all goes well for you, remember that I was with you. Please show kindness to me by mentioning me to Pharaoh, and get me out of this prison. 15 For I was kidnapped from the land of the Hebrews, and even here I have done nothing that they should put me in the dungeon.”

It is true.  Joseph had not done anything wrong.  A lie had put him in prison.

Genesis 40:16 When the chief baker saw that the interpretation was positive, he said to Joseph, “I also had a dream. Three baskets of white bread were on my head. 17 In the top basket were all sorts of baked goods for Pharaoh, but the birds were eating them out of the basket on my head.”
18 “This is its interpretation,” Joseph replied. “The three baskets are three days. 19 In just three days Pharaoh will lift up your head—from off you—and hang you on a tree. Then the birds will eat the flesh from your body.”
20 On the third day, which was Pharaoh’s birthday, he gave a feast for all his servants. He lifted up the heads of the chief cupbearer and the chief baker. 21 Pharaoh restored the chief cupbearer to his position as cupbearer, and he placed the cup in Pharaoh’s hand. 22 But Pharaoh hanged the chief baker, just as Joseph had explained to them. 23 Yet the chief cupbearer did not remember Joseph; he forgot him.

I am sure it crossed his mind that what Joseph said came true, but for whatever reason he did not mention him to Pharaoh.

Dreams are just one way God can speak to and through his people.  

Matthew 2:21 So he (Joseph) got up, took the child and His mother, and entered the land of Israel. 22 But when he heard that Archelaus was ruling over Judea in place of his father Herod, he was afraid to go there. And being warned in a dream, he withdrew to the region of Galilee. 23 Then he went and settled in a town called Nazareth to fulfill what was spoken through the prophets, that He will be called a Nazarene.

Acts 2:16 this is what was spoken through the prophet Joel:
17 And it will be in the last days, says God,
that I will pour out My Spirit on all humanity;
then your sons and your daughters will prophesy,
your young men will see visions,
and your old men will dream dreams.
18 I will even pour out My Spirit
on My male and female slaves in those days,
and they will prophesy.
19 I will display wonders in the heaven above
and signs on the earth below:
blood and fire and a cloud of smoke.
20 The sun will be turned to darkness
and the moon to blood
before the great and remarkable Day of the Lord comes.
21 Then everyone who calls
on the name of the Lord will be saved.