Spiritually mentally and physically

So this girl says that being a mother is spiritually mentally and physically different then when not having kids. Does anyone know what she’s talking about? She says since I don’t have kids I don’t understand what she’s talking about so I want opinions from moms what that means if anyone know what that means. Also I would like to add that she says every single mom goes through the same thing spiritually, mentally and physically and since I’m not a mom I wouldn’t understand. (Mind you I’ve been struggling to conceive for 4 years and get heartbroken every month.)