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.
No matter the reason, drug use can quickly become drug abuse, which eventually leads to a chemical dependency to the drug. This happens because the body can become tolerant to a drug relatively quickly. What this means is that it takes more and more of the drug for the user to feel the same effects. In seeking that initial high, the body becomes dependent, and thus addiction takes hold.