Ask HN: What are some popularly held cs misconceptions?

[jrosenberg99]

Talking about mistakes/misconceptions can sometimes be as elucidating as talking about facts.

Here is one that got me:

In Java this sometimes occurs:

Integer a = 10; Integer b = 10; a == b; // returns true

Integer a = 1000; Integer b = 1000; a == b; // returns false