A good pour is the key to a great tasting beer. This guy actually gets paid to be a 'beer sommelier' or beer expert. Just like wine, beer has many complexities to it's ingredients, it's creation, and it's flavor. These complexities are enhanced with a good pour...
Pouring a cold brew from a bottle or a tap into a glass the wrong way can give you a stomach ache. You’re not only pouring beer into your glass, you’re pouring carbon dioxide into it as well. When you pour beer slowly and carefully, the CO2 gets trapped in the beer.
All those bubbles in the beer go to your stomach and can cause you to get bloated, which may cause a stomach ache. The CO2 trapped in the beer is equivalent of 2.5 times the volume of beer as opposed to if the carbon dioxide was released during the pour.