If you can't even draw a straight line is there any hope of learning to draw at all?

absolutely! There is an academic side to art. Alot of famous artist couldn't draw or paint, but their works are still seen as "talented." Besides, it's all in the practice you put into it. If you get a good professor and take classes you'll be amazed at how much progress you can make.

First, let me say that as an artist, there is no "right" or "wrong" way to create art. It is all interpretive by you and by the viewer. I am a professional portrait artist, and I can't draw a straight line! I consider art to be something mastered with the creative (right) side of the brain. Perfectly straight lines I consider to be in the logical (left)side of the brain. I have a few ideas for you: Try sketching. Instead of drawing a firm line, try moving your pencil back and forth lightly in the direction of a line. This creates an illusion of a line, instead of stressing yourself trying to perfect a line. Try using different mediums. If drawing with a pencil isn't working out for you, try drawing with India ink (looks beautiful when accompanied with water color), you could also try painting with acrylic paint, oil paint, pastels, etc. Whatever you discover you like using the best, it is going to take time to master. It is rare to create a masterpiece with your first shot. Give it a lot of practice so you can learn what you do well, and not so well. Tweak it every time you try something until you have found your perfect medium and are comfortable doing it. Oh, and if you aren't learning from guides very easily, try classes, or else just free hand it and see if you can train yourself just with willpower and raw talent.

Nobody can draw a perfect straight line. Anyone can draw, all you need to do is find your particular style, not all good art is an exact replication which is why we have different genres of art.

art is not just whether you can draw neatly or straight. If you want to draw what you see in your head just try, don't try doing something that you can't see. Do some abstract art. :) In my college we have an art room full of different types of art. Some just consist of scribbles that are in there own way art. Also to do art you don't have to draw, you could paint or stick things together

Well, there aren't that many straight lines in nature anyway, so there's hope. Take some classes. You need some expert guidance.