adds warning and purpose

README.md

@@ -3,6 +3,14 @@ ready
 
 NodeJS mixin to add one-time ready event
 
+## Purpose
+Events are great. You should use events, but not for signaling ready! Ready implies state, and once you are ready, you stay ready.
+
+This is a module for everyone who has bound an event handler.on('ready', function() {}) that doesn't execute because you added the handler after the 'ready' event already fired.
+
+## Warning
+If you use Ready for inheritance, you must have 'ready', '_ready', and '_readyCallbacks' available on your class. Ready will stomp on these variables if you're trying to use them in your class.
+
 ## Example
 ```javascript
 var Ready = require('ready')
@@ -34,4 +42,10 @@ myClass.ready(true);
 myClass.ready(function() {
   console.log('I came late to the party, but I want to execute too!');
 });
+
+// Ok, you can set the ready state to false now as well... for whatever reason
+myClass.ready(false);
+myClass.ready(function() {
+  console.log('I will not fire until you set ready to true again');
+});
 ```