What other programming languages have you used? Any language that implements its own memory management system (python, lisp, scheme, etc.) will exhibit similar behavior. It's only the languages like C, C++, etc where you have fine control over memory allocation/deallocation where you mayn't see this behavior. But even then, it depends on how the language is implemented. Most C implementations (for instance) won't exhibit this behavior, but as soon as you're using a C interpreter that might have some memory management scheme, all bets are off.