If your opinion of your effectiveness at work differs from your co-workers, forbes.com contributors David Sturt and Todd Nordstrom offer six reasons why. Here are three of them.

• You avoid expressing your opinion. If you’re a “go with the flow” kind of person, your team may see you as someone who doesn’t care enough to engage and invest in the team. Make sure you stand for something and take part in the back-and-forth that drives great ideas.
• You’re always on your phone, picking it up or being distracted by incoming messages. Those brief interruptions actually make it harder to stay focused and on task. Put your phone away.
• And here’s the most surprising point: you undermine your productivity because of simple dehydration. Studies show that mood and cognition suffer when you deprive your body and brain of water. So, make it a point to drink water throughout the day, even if you’re not thirsty.