1. Going back to work relatively early, and staying in touch with my work while I was out on my (3 month) maternity leave helped me adjust to becoming a mother and I think it helped keep me from tipping over the edge from "sleep deprived and more than a little overwhelmed" to "seriously depressed and in need of help".
2. My work life has gotten easier as I move up the food chain. Now, the work itself has gotten more challenging/stressful, but the actual experience of working has gotten much easier. I have far more control over my schedule and much more leeway to work from home from time to time. I also have more negotiating power when I want something like a few days off without pay (because I've exhausted my PTO and still want a vacation, for instance). I try to keep this in mind and flow the freedom down to the people who report to me, but I am sure I am not perfect at that, and a lot of bosses don't even try.
4. I wasn't all that concerned about missing milestones that happened at day care. I figured seeing the third rollover was as cool as seeing the first one. As it happens, I think I say the first crawls for both kids (in both cases, towards my laptop...) and the first steps. If day care knows otherwise, they aren't saying.
5. I don't care if my nails are manicured. I don't care if my hair is a little bit past the optimal time for a trim. I didn't care about these things before I had kids, either. Whenever some other mother is speaking wistfully about how hard it is to get time for a manicure these days, I just smile and nod. But to be fair... I speak wistfully about how I can't find a martial arts class that fits my schedule. So, to each her own method of stress relief, I suppose.
Note that I am not saying that these are true for all women. Just for me. Do you have any unmarketable truths about your life that you want to share? They don't need to be related to being a mom, or working- just things that our culture assumes is true for "all" people like you, but that aren't actually true in your case. Leave your unmarketable truths in the comments, if you'd like.