So... you want to be a barkeep

 6 months is both a long time and really quite short. Relatively speaking, in a career, it's one of the shortest times and marks the path with a humble beginning. In terms of bartending, it's hardly enough to get your teeth wet. But in terms of serving the general public, it's really quite an easy job to learn. Things that come with time are speedy habits, excellent sales techniques, deep knowledge of your product and your clientele, and maturity/refinement in stressful situations.  

The knowledge of the job that comes quickly should be perspective of what is needed, such as glasses, ice. The simples, and the foundation. After that, pouring a great beer with a perfect head and properly serving a wine both at a table and out of the counter count for quite a lot of the sales one will be making at the bar. Generally, the hard customers stick out, but the ones that fill out the fodder are the ones that are easy to please, purchase another drink, and don't need anything else from you for a solid 10 minutes. Refilling water is a great way to show service though, along with many other tips that are doable in a more relaxed pace environment. 

Working as a bartender can be quite rewarding, especially if you're more task oriented, and in general environments don't need to think too much creatively. What I've seen is that this kind of person is usually into drinking, might enjoy the act of serving the drink, and can smash things out quickly. While I see the utility of this kind of bartending, I think it's the kind of career that someone either gets stuck in, or uses as a side career. My general advice to these kinds of people is be in school full time, or find something else to do. 

However, if you've a mind built for creativity, love upselling, guiding questions, customer interactions, strange and weird combinations and pleasing someone with your creation, I suggest that you consider bartending. Restaurants that need a bottom line more than they need skillsets will usually provide you an amazing way to get your teeth kicked in, and an experience between the mad rush, the banterous coworkers, and the balancing act of hundreds of glasses is frankly some of the most stressful fun one might be able to have. But it is heavily taxing physically. But push through with a goal of a year, and you'll be transferrable, and easily marketed. If your attitude is positive, you'll also start getting to know your local peers, and then the clam is your oyster.... or something like that.