There have been a few articles recently complaining about people who complain about being busy. They offer the keys to unlocking what people really mean when they say they're busy, usually that they're super-important. There is another thing that "I've been really busy" means: I'm sorry. I'm sorry I haven't kept in touch. I'm sorry I missed your concert/art show/party. I'm sorry I've been mentally absent, unfocused,…
"I'm busy" just sounds like "I have more important things than you."