History time: In 1972, David Parnas wrote a paper about "Information Hiding," and a few years later Fred Brooks wrote The Mythical Man-Month, possibly the most

History time: In 1972, David Parnas wrote a paper about "Information Hiding," and a few years later Fred Brooks wrote The Mythical Man-Month, possibly the most influential book about software engineering, which largely discounted the value of information hiding. 20 years later, in an updated anniversary edition of The Mythical Man-Month, Brooks wrote "Parnas was right, and I was wrong about information hiding." Coming from Fred Brooks, this was an enormous admission! What is this amazing "information hiding?" It is separating interface from implementation, leaving one public and the other private. It is accomplished, among other means, by marking things "private." This is the one thing in 20 years that Brooks found to be valuable in increasing programmer productivity in terms of essential complexity. Marking implementation details as private reduces the essential complexity of the code. By the way, in some of your comments you talk about "everyone" having access to things, as if that makes a difference. Marking things as "private" is not about closing off access to particular people. It's not a security measure. It's about reducing the complexity of a given class by ensuring that the number of access points to that class are limited. That could affect other teams, sure, but it could also affect future-you, or you-working-on-other-class.