Andy has a knack for voicing his opinion at the drop of a hat, he's a blunt individual and not exactly eloquent. It's something I love about Andy, you always know where he stands. However, this doesn't usually go well with the females of the species.
Men have a tendency to speak strongly about any subject available, it's something we do in an attempt to appear knowledgeable, or in control of things, or because we like to hear ourselves speak, who knows. The problem with this is our actual feelings about the subject often don't live up to the intensity with which we discuss said subject. As men this is how we interface with each other, hearken it back to the days of beating chests and grunting to communicate.
Women see it differently. Women use your opinions to gauge what kind of person you are and how you will think, feel, and react to her opinions. They also gauge how strongly you feel about a given subject by how strongly you discuss it, you can see how this is counter-intuitive to man's natural discussion style.
On top of that, men also like to be aggressive and negative about subjects we don't like, or maybe don't understand. We'll say things like "that's stupid", or "I hate that", etc. As my mother would say...that's ugly. I know as men we don't see it this way because we're just excited, or is it excitable? Women see this as you being nasty, aggressive, unrestrained, and yes...ugly.
So what's the point? You have three options:
1. Reserve your opinion if you feel it's going to come out as negative or aggressive. I shouldn't have to say this, but if you don't know what your talking about then you shouldn't be talking.
2. Agree with your woman if you feel the same way, or if you don't care either way. Don't say you don't care either way, agree with her. I shouldn't have to say this but don't make it obvious you're just agreeing with her.
3. If you disagree with her opinion or feel strongly about a subject and must speak truthfully then use your words eloquently. Say " I'm not sure I agree with that" or "from what I know about it" and then voice your opinion ELOQUENTLY. Always discuss a touchy subject in the manner you would a school subject and not as something intensely personal.
This advice is intended for the beginning stages of a relationship, once your woman is into you enough to overlook your neanderthal tendencies then you may start to reveal your true opinions, cautiously.
Follow these guides and you should come out looking like an intelligent, controlled, confident man. Good luck!