Seriously, all of these "my BTC was sent an address I don't know" posts are ridiculous. It's like at least once a week about change addresses.
Whats so ridiculous about those questions? Its a hard to grasp concept that bitcoin comes in lumps and is not just a balance where one can deduct
a certain any amount. The questions only shows that most wallets do a very good job in hiding the details of the implementation from the user and that blockchain explorers are an unreliable tool when trying to assess a wallet.
It's ridiculous that it's constantly happening. If people constantly have to ask you have a serious design flaw, but I don't expect the fucking morons around here to understand that.
I have no idea if you're complaining about the people asking the questions, or that change address implementation is flawed in some way, or if you're stating that the blockchain explorers are flawed. Who exactly are the morons to whom you're referring?
DannyHamilton's explanation is very good. You should not be using a blockchain explorer to track the operation of your wallet. If you are going to look at the blockchain explorer, you really should have some idea of the workings of the protocol to know that transactions are composed of inputs and outputs.