It is extreemly important to share your opinion with others. Whether it's your friends, family, or colleagues. This is a way that others can get to know you, and where you stand on on certain issues. Putting in your opinion can change your situation from complete compliance, to having certain aspects to go the way you would like them to. However, it's necessary to keep in mind what type of audience you are giving it to.
An opinion is also a way that people may judge you. This is why you need to be careful how dramatic you're opinion is. It's very unfortunate that there are so many people that have the mind set that,"They don't care what people think." For example, if you were to say to your mother that you don't agree with the nineteenth ammendment, you will without a doubt affend her, and possibly could result in you getting a nice beating. The point there being that you need to be careful about who you may affend when stating your opinion on certain issues. On top of that many people may not even want to hear what your opinion is at all, but if you're the type of person who needs to get it out there, just make it brief; people will give you more respect.