TL;DR: The fastest algorithm looks at every element once, keeping track of the largest one seen so far. Details. Intuition tells us that any correct algorithm must look at every element in the array, that's why we can't do better. Let's find an actual proof.
Drugs are addictive  because they either mimic or stimulate the production of brain chemicals that cause feelings of pleasure. After a period of time, your brain adjusts to the higher levels of the chemicals, and it becomes necessary to use more drugs to get the same effect.
But over time, opiates trick the brain into stopping the production of these endorphins naturally. At this point, the only way a prescription drug addict can experience positive feelings is by using the drug in question. This process is the reason why opiate-based prescription drugs are so addictive.