What does the saying "You can't see the forest for the trees" mean?

I have a theory but I'm not quite sure. I think that it means that you aren't enjoying life because you are trying to fix all of the problems.

You can't see the big picture because you're sweating the details.


An expression used of someone who is too involved in the details of a problem to look at the situation as a whole: “The congressman became so involved in the wording of his bill that he couldn’t see the forest for the trees; he did not realize that the bill could never pass.”
http://dictionary.cambridge.org/dictionary/english/can-t-see-the-wood-for-the-trees

Definition: overly concerned with detail; not understanding the whole situation.

Explanation: Used when expressing that a person is focusing too much on specific problems and is missing the point.
http://esl.about.com/library/glossary/bldef_130.htm

In the UK we say "can't see the wood for the trees".
http://www.usingenglish.com/reference/idioms/wood+for+the+trees.html

You are so fixated on what is directly in front of you, the tree (the finite details), that you can not see the big picture, the Forest (life).

"A person who is a sensing type may not be able to see the forest for the trees while an intuitive person may not see the trees for the forest. Sensors see the actuality and intuitives the see the possibilities. Sensing and intuition provide information about the world but very different sorts of information. People operating from these two functions see the world in very different ways."

http://www.phrases.org.uk/bulletin_board/21/messages/886.html

I'll second Dave about the UK version.