I know most parents who offer parenting advice do so with the best of intentions. Honestly, I appreciate the goodwill behind these kind gestures, like someone is thinking, “Surely I can swoop in like a superhero to help you fix your problem, if you'll just allow me three minutes of your time.” That said, I’m at the point (and I suspect other moms are, too) where I know the pieces of “advice” that every toddler mom dreads hearing are coming my way, and instead of being grateful for the "help," I am mentally preparing myself to handle that "advice" accordingly.
Of course, sometimes unsolicited advice can be a good thing, in the same way that a broken clock still tells you the correct time twice a day. For the most part, though, I find myself just trying to grin and bear any interaction with another parent that involves them, essentially, telling me how to care for my toddler. As smart and as insightful as some of the advice might be, the fact remains is that no one else knows my kid the same way his dad and I do. As well-intentioned though they may be, the people offering their "help" don't know the full extent of our parenting efforts so far, or our preferred parenting techniques and styles, so it's all just lacking.