If you make a person do the same thing a million times, they'll be lucky to only screw it up once during their tenure. That's why there's insurance. Even surgeons, with lives on the line, can make horrible mistakes that will haunt them for years and perhaps even to the end of their days. It's both a blessing and a curse as a part of being a person. Dealers at the casinos are no different from you in that they can also commit tremendous errors. Gambling remains inherently risky, sometimes involving tremendous amounts of luck and chance and on a busy day, can involve eight people or more, depending on the game. Occasionally, your bet will get misplaced or even attributed to a different player or they can even think you bet more than you actually intended to. This would, generally be considered a bad and horrible thing. This is why a common gambling tip is to watch your dealer when playing games like Roulette or similar games.
This is what they do. Dealers are trained and drilled to make sure that the rules of the game are instinctive and come to mind in a moment, but no amount of training can make a person perfect at their job. How the game is treated and handled can even come under the attack of chance and can skew the odds even further away from you. Misplacing one chip can mean that you just inadvertently lost fifty cents or, at worst, that may mean that you lost two thousand and five hundred dollars. More heartbreakingly, that could mean that someone else would get your bet. If you don't follow this gambling tip and keep your eye on the ball, you may end up losing far too much. It is then of utmost importance that you pay attention to your bet.
Of course, you may be there for the fun and the sun and the casino and the experience. You want to relax - but that doesn't mean you should be careless with your chips and your money. A dealer's expertise is cannot fight against chance. At the end of the day, you must ultimately be responsible for your best and thus, take the initiative in these matters to prevent catastrophes from happening. Many games like Texas Hold'em tell you to always pay attention - any game, truthfully, could make full use of that tip. Keep that in mind and you can avoid numerous disappoints.