What is it with people!?

Ok so I have noticed a distinct pattern lately when dealing with people that manifests itself most heavily when using e-mail as a communication medium. This pattern is that when asking someone multiple questions in an e-mail message, their response will rarely ever include more than one answer to one of those questions. Typically the response will only ever answer the last question. WTF!? the whole point of e-mail is to be able to communicate more information faster with a record of correspondences for reference. Why the hell will people not reference the message they are replying to while they are typing their reply. Am I going to have to start sending multiple messages back to back to the same person with only 1 question each. HOLY SHIT PEOPLE! Is it really that hard to formulate a response that you cannot be at least mildly thorough about it? I really hate this because now I have to e-mail them back and be like "Um what about Questions 1-3? You only answered number 4."