You know those Corona commercials where you see a scantily clad couple chilling by the water’s edge, relaxing and taking in the sun? Those commercials are designed to make us buy beer, and they do that by associating the product with a feeling of calming relaxation.

But why is an image of the ocean so relaxing? Have you ever stopped and wondered why humans find bodies of water so beautiful and calming?

It’s pretty simple, actually. Our species is designed to benefit from the water, so it becomes genetically advantageous for people to be attracted to water. Here are 5 reasons why humans are irresistibly drawn to water.

5. Clams Make Your Brain Grow

The one thing that differentiates us from the animals is the fact that we have huge brains. Because we eat meat, it’s much easier for us to get the fats and proteins that we need to build our giant brains. Crabs, clams, and fish are rich in omega-3 fatty acids, which dramatically increase brain growth.

Over time, humans who preferred seaside locations got better nutrients and stayed healthy, so they passed on that proclivity to their offspring.

4. Fish Literally Makes You Happy

This aspect is pretty similar to #5 on the list, but different enough to be its own reason. Seafood not only makes your brain bigger, but it also makes your brain happier. Scientists have discovered a direct link between the amount of seafood eaten and depression. Cultures and locales that eat buckets of fish stick will smile a lot more than their cousins farther inland.

3. Humans Aren’t the Only Species to Love Water

A lot of the advantages that come from water apply to other animals, so bodies of water indicate excellent hunting grounds. Humans who have lived near bodies of water have a much easier time hunting game, particularly around rivers and lakes. It’s much easier to maintain a balanced diet when there are an abundance of mammals, birds, fish, and plants growing at water’s edge that can be harvested for food.

2. Waterfalls are Better than Lakes

I’ve been to Niagara Falls. It’s beautiful beyond any mere description, so I wont even try to describe what it was like. Is there a reason why people fly from all over the world to see Niagara Falls, but most people won’t even cross state lines to see Lake Erie or Lake Ontario, the 2 lakes that compose Niagara Falls?

Yes, actually. The only way to have flowing water is from rainwater, and rainwater is just about the freshest, healthiest source of water available to early humans. Famous poet William Blake once wrote, “Expect poison from the standing water,” which helps to capture this concept. We are drawn to waterfalls because we unconsciously associate waterfalls and flowing water with clean, healthy drinking water.

1. It’s Like Returning Home

I thought about making the #1 reason “Because we need water to live,” but that’s just a little bit too obvious. Let’s stir things up a bit by talking about evolutionary theory.

Bears and dogs are both land mammals, while dolphins and seals are aquatic mammals. Notice a difference between the two? Dolphins and seals are completely smooth, an adaptation that makes it easier to swim in water. In fact, virtually every hairless species of mammal (there are a few exceptions, like the naked mole rat) spent time in water.

So, why are humans virtually hairless compared to other apes? The favored theory now is that our ancestors spent most of their times swimming around. Coincidentally, that also explains why babies know how to swim.