True mastery of software development comes about with experience — some good, some bad. It's that latter category of experience, the "gotchas," that leave us with bumps, bruises, and battle scars. The aim of this article is to help you avoid some of those painful mistakes, which can lead to the difficult and tiresome process of searching for software bugs. Here, you will find an overview of the top 10 most common pitfalls, as reported by SAP's help desk over the past three years, that you are likely to encounter when dealing with ABAP fundamental operations and data types, like simple arithmetic and conversions, predefined ABAP data types, and flat structures.