Shameless plug, but I enjoy writing natural, intuitive explanations of math & programming topics. Try this intuitive guide to e if the true meaning of that constant has eluded you:
In my experience, the biggest hurdle in math is understanding what the notation is saying. Usually the ideas are pretty straight forward, though clever.
http://betterexplained.com/articles/an-intuitive-guide-to-ex...
Sometimes you need to "forget" what you know and come at things with a beginner's mind.