Reading comments is an art form nearly as useful to the maintenance programmer as the ability to read code. A few tips to help you read comments:
Take everything you read with a grain of salt, especially if the code is working.
Maintain the comments as well as the code.
Think of identifiers as short comments.
Even better, try to make the code segments short and clear so that comments are unnecessary.
When a comment says must, it's a clue to go looking for a piece of code that isn't what the comment says it must be.