If you dress appropriately for your job, you will not only impress people around you, more importantly you will feel good about yourself. Going to an office in an oversized t-shirt and a pair of jeans will not portray a good image of you. The same way you will go to a construction site in your suit instead of overalls. You have to dress according to your occupation. It is also important that you dress according to the time of year and weather. You do not want to go the office wearing thick jacket and shawl during summer (unless you are getting cold every time whenever you’re in the office.)