Really? You may wonder. This is 2024 and do we all not know Java already really well. Most of us do and yet there are so many things we tend to not realize until those things bite us in the back. This is not an introductory session on Java but one in which we will take existing code, discuss its behavior, look into surprises it holds. These are scenarios that either the speaker has stubbed his toes on or things he has been other developers stub their toes, from practical every day realistic code. We will take a number of working examples, ask you to identify the behavior, then run the code to see what it really does, and discuss the underlying concepts or the lessons we need to carry forward to avoid falling into traps or developing code that may cause issues in the future.