Not only that, but disagreements about what something means is often a Very Hard Problem, and even when courts judge something one way or another, there are many people who _disagree strongly_, and hope to either change the judiciary, or change the laws to more explicitly favor their position. (This is, as far as I recall, how one is supposed to resolve disagreements about what the law _should be_ in our country.)
For example, many reasonable people disagree on whether the second amendment's wording is intended to mean that _everyone_ should be able to bear arms, or whether it's intended to mean _only people in a militia_, and there also seems to be some disagreement on what "arms" means. I can see how a reasonable person could interpret it in either way. Such disagreement seems to have been something which the founders themselves shared.
tl;dr: People disagree both on what we currently interpret words in law to mean, as well as on what the _intent_ was when it was originally written.