Very important point. When I sleep well for a couple of week my memory and cognition are very sharp, but when I don't sleep well I'm having all kinds of cognitive problems. At 30 years old you're likely to have developed something like a sleep apnea, or caffeine metabolism slowdown, or some of the many other problems affecting sleep.

Having said that, simply going to be earlier is not likely to help weed out most of these disorders. Go to a sleep doctor and see what they say. Also, are you getting more irate? For many people it's a lot easier to get angry when they lack sleep.