Everyone has something to say. My mother-in-law, random strangers at the grocery store, people in comment sections online. I did not ask and yet here we are. How do you all deal with it without losing your mind or your relationships?
Oh @QuantumThread I felt this in my soul 
My personal rule is the nod and move on. You smile, you say oh that is interesting, thanks,’ and then you do exactly what you were going to do anyway. It took me a while to figure out that most people giving advice are not really talking to you, they are talking to their past self. Your mother-in-law is not criticizing you. She is reliving her own parenting years and feeling a little bit nostalgic.
Once I started seeing it that way, the advice stopped feeling like an attack and started feeling more like… background noise I could just let pass. Does not mean it is not annoying. It absolutely still is. But it bothers me a lot less now…
My personal favorite is when a stranger at the park tells you your kid needs a coat and your kid is literally sweating lol
I have developed what I call the Polite Wall. It is not quite agreement and it is not quite disagreement. It is just a face. A calm, neutral, absolutely unreadable face. Combined with the phrase we will keep that in mind which means absolutely nothing and commits to absolutely nothing.
Let me paint you a picture…
It is Sunday dinner. You have just finished telling your family that your toddler has been sleeping through the night finally. Before the words fully leave your mouth, your aunt who has not had a baby in 27 years starts explaining how you should have done sleep training differently.
This is the moment. You have two paths. One involves a lengthy debate that will ruin dessert. The other involves nodding slowly while mentally planning what you want to watch on TV later.
I always pick path two now. Not because I am a pushover. Because I have learned that no debate at Sunday dinner has ever changed a grandparent’s mind about anything. Not once. Not ever. Save your energy for the kids 
I think the part that gets to me most is when the advice comes from people who mean well and genuinely care. That is harder to brush off than the random stranger stuff.
My mother-in-law is not a bad person. She raised three kids and she loves our daughter more than anything. But sometimes her advice comes out as criticism even when that is not what she means. And that one stings a bit.
What has helped me is separating the message from the delivery. When she says you should feed her earlier in the evening, the underlying thing she is saying is I want your daughter to sleep well and be healthy. That part I can actually appreciate even if the framing is annoying.
Does not work for strangers at the grocery store obviously. That is just noise 
@DevSyncer the Polite Wall is real and I respect it deeply 
I have my own variation which I call the Echo. Someone gives me advice, I just repeat the last few words back to them with a thoughtful expression. Oh so you think earlier bedtimes. Long pause. Interesting. And then I change the subject. People feel so validated by it. They walk away thinking they really got through to you. You have agreed to nothing. You have promised nothing. You are completely free.
The trick is keeping the thoughtful expression going long enough that it reads as genuine consideration rather than barely contained frustration. That part takes practice 
Honestly the most useful thing I did was just decide which relationships were worth the energy and which were not.
For close family, I do put in the effort. If my mom says something that bothers me I will actually tell her, calmly, that we have made our decision on this and we are good. Takes one uncomfortable conversation but it usually sticks.
For everyone else acquaintances, strangers, comment sections online, I just do not engage. Not worth it. You will never get those minutes back and nothing changes.
The mistake a lot of parents make early on is treating every piece of unsolicited advice like a threat that must be addressed. It does not. Most of it will stop on its own if you just do not react to it 
@QuantumThread the mother-in-law part especially, that is a whole separate layer 
Because with strangers you can just walk away. With family you have to sit across from them at Christmas and act normal. That makes it a lot more loaded.
My method: smile, nod, keep walking 
I have been doing this for three years. My kid is fine. Nobody’s feelings got hurt. I have not started a single argument at a family gathering.
Highly recommend.
@CloudKernel11 made a point that I keep coming back to, the idea that people are often talking to their past selves. That reframe genuinely changed how I hear advice from older relatives.
My dad grew up in a very different time. His parenting advice is basically a time capsule from 1987. When he starts talking about how kids these days are too soft or whatever, I now just think he is telling me about his experience, not mine. And I can respect his experience without applying it to my kid.
The one scenario that still gets me though is when advice comes from someone who does not have kids at all. A coworker once told me I was overcomplicating things with my daughter’s sleep schedule. She has a dog. A very well-rested dog, I am sure
That one I have not fully figured out yet
I think the thing nobody says enough is that the advice itself is almost never the real problem. The real thing that bothers most parents is the implication underneath it that you are not doing it right, that someone else knows better, that you need to be corrected. Not everything needs a response. Not every comment needs to land. You are the parent. You get to decide what sticks 
I have been doing it all wrong. I actually try to explain myself and engage and you know what it does? Nothing. Absolutely nothing. They just come back next time with the same advice plus a story about how their neighbor’s kid turned out fine doing it their way.
Starting tomorrow I am going full Polite Wall. New era. No more explaining my parenting choices to people whose main qualification is that they were once alive during someone else’s childhood 