When you become a parent everyone loves to give you their 2 cents of advice. You will learn very quickly that whatever you are doing, you must be doing it wrong. Everyone wants you to do what they did as a parent, because they think its best. After all it worked for them. But when do you know if its advice you really should listen to? How can you tell the difference. One easy way: it does not benefit the giver in any way. If the person giving you advice tells you that your child's eye is wandering and you didn't notice and suggests getting it looked at - that's advice you should listen to. Its not like the advice giver is trying to get you to try the latest sleep positioner that they love, or get you to go to their dr because hes simply the best. The advice only benefits the child and not the giver in any way.
If there is no benefit to the advice giver remember that they are not trying to slam your parenting skills any. If you have given your baby solids and they start screaming in pain a while later and someone suggests holding off solids because your child might be too young, it might be something to listen to. Its not that they said they didn't start solids for a full year and their child never screamed. Its not a reflection of your parenting skills, its simply someone looking out for your baby when you might not know any different.
Consider the source, if the advice comes from someone you trust, someone who loves you, or someone who has always looked out for you, why would they give you advice if it weren't for the best? If you are the advice giver try to be tactful. We all know you are just trying to help, but they don't know that. They are already on the defensive after listening to crazy lady at Walmart tell you that all babies should sleep with their head pointed north.