While it is important to have a plethora of skills in the work world and when applying for jobs, some can be seen in a negative light. It is important to be aware of that and present yourself to your best advantage.
On its face being able to multitask is a positive skill. You can do more than one thing at a time. However, it can also be seen as someone who lacks focus on finishing something and flits from one thing to another. The best thing to work on is being able to prioritize each task in order of importance.
When someone says they have a strong work ethic they assume that everyone will see them as hard worker. Well, you can be a hard worker but an ineffectual one. Being at the office the longest does not mean you got the most done or at the best quality. Make sure you just don’t have limited time management ability.
Working effectively is more important than working overtime. Over work can lead to stagnation and burn out. Work hard when it is called for and take some time off when appropriate.
A can-do attitude is seen as rather juvenile in the work world. Realism is appreciated by bosses. It is a detriment to the company if you promise something on too quick of a time frame and then do not get it done.
There are others relying on the date given that you had no real chance to make. Learn to make a better assessment of the length of tasks. Honesty is better.
While confidence is important, out and out bragging in the office is not a good idea. You do not want coworkers to be jealous or resentful. There is a line between making sure management knows you are contributing and over doing it.
Just because a skill sounds good does not mean that it always is one in the real world of work.