Dreams. A Cry for Help or a Way to See the Future?

I'm going to first say that I have no idea what the meanings of the messages dreams are supposed to give us. Some friends say that it's just your brain thinking without your control and that's why dreams can be the weirdest shit. Some say that it's you remembering what you did that day or what you did five years ago. I don't know! I just want to know what these mean?! Then again... Maybe I don't?
The first one goes back to the herione days. I was in class, computer to be exact, and I get a text message. It's from my mother and it says, "Son! I found a bag and looks like heroine!" My mother doesn't know what it looks like, I'm pretty sure, so I responded, "It's probably your husbands pot. Both Nelle and him like to smoke it a lot." Then that's when the teacher caught me texting; which I hate doing... A LOT! And told me to leave class. If you have this computer class you'll know that he'll actually do that. Hah. End of dream number one.
The second was even more weird because it took place Tennesse; I automatically knew it to when the dream first started, in a house that me and the main girl from Weeds, Mary-Louise Parker, were moving out of. She looked at me strangly and asked if I knew what to do in case of a "dow bite." I was so confused that I kept on asking what that meant and she started crying because it ended up that she meant "Black Widow bite," and enevidable death. I tried sucking the poison out but it wouldn't work so she ended up dying and I was alone untill the dream ended.
The third is dumb and I'm only going to say that it was that my laptop worked and it was super fast and I had a lot of e-mail.
The fourth, however, was a little sad. I was hanging out at my friend Annable Alberta Long Freeman's house that's right above Torch on King Street. There was a third person view of her and I arguing. All of a sudden I get a phone call and I drop the phone with disbelief. It was Evan... He's in a coma right now. I answered it and it was actually him! I ran to my car and went to see him and we hung out. We didn't drink, we didn't do drugs, we just sat and spoke and HUNG OUT. I was so happy. I thought that this meant I was going to die because apparently Evan was supposed to be in a coma for life. BUT I got a phone call from my secret bestfriend Carly Stallings saying that he's starting to move and asking if I could meet her at the hospital he's at. I'm so happy.