The advice about over-tiredness is always changing when it comes to babies... is it a thing? is it the end of the world? is there any science involved in this whole concept that a person can be TOO tired?

Nobody talks about how lonely it can be if you're the only one with a child who continues to be wakeful when everyone else around you seems to be getting more sleep. And then you might feel the pressure to sleep train if you ever talk about how tired you are. Perhaps your partner or someone else...