In the workplace, there are always a million things happening at any given time. You have reports to complete, clients to speak with, political drama to tend to, and so on. One thing to remember is that, despite all these huge things that may be going on at any one point, it is the little things that can shape perception of you in the office.
Little things are just that; small, seemingly inconsequential things that aren't terribly important. One such thing that many people have been guilty of over the years is clicking "Reply All" instead of just "Reply". I've worked at a place before where someone clicked reply all seemingly every time they sent an email. Most of the time it wasn't a big deal at all, but it was certainly a little obnoxious to get repeated emails that had nothing to do with you. This person was not a bad worker by any means. In fact, that person was very capable with what they did. The sad truth is that, because of a small mistake like that, people took this person far less seriously than they otherwise would have.
Make sure at whatever job you have that you take care of these little things. You don't want to garner a reputation because of something ultimately inconsequential.