26th March is Document Freedom Day. You can completely ignore it without getting harmed or abused or blamed for being indifferent. But if you know have ever faced a scenario when you could not open a document because did not have a specific office suite, knowing more about document liberation might be worth it.
Documents are a critical part of our life. Most of the times they are the meat of what our computers do as desktops. Unfortunately the software world is good at trapping you in their own world by using proprietary formats, which only their tools can read and write. The only way to get out of this is to start using Open Standards, which removes all patent and proprietary barriers and encourages its availability on all platforms. Which means that you can open and work with documents created by others using an application other than yours. And you can be assured that someone else can work with the documents that you send to them. This interoperability is good for you.
ODF is one such open format which is accessible through multiple office suites on multiple platforms. If you have not worked with it yet, give it a try to help yourself.