If you are checking a feed like email, or chat, you are expecting a new item. If you fail to get a new item 9/10 times you check the feed, it certainly makes sense that you may feel stressed or feel like you have less control over things. You can't control when the items come into your feed. 9/10 times, you are hyping yourself up to expect something, and then getting disappointed when it's not there. I think this kind of result is true for anything that requires waiting for something out of your control. The train, the doctor's office, replies to your comment, etc.