I believe this is how it works. From what I remember reading, there is a proxy class generated that intercepts all requests and responds with the cached value, but ‘internal’ calls within the same class will not get the cached value.
From https://code.google.com/p/ehcache-spring-annotations/wiki/UsingCacheable
Only external method calls coming in through the proxy are
intercepted. This means that self-invocation, in effect, a method
within the target object calling another method of the target object,
will not lead to an actual cache interception at runtime even if the
invoked method is marked with @Cacheable.