I really wish someone would have set me straight on the sleep deprivation. I could've used a professional momma mentor too as I may have continued to work if I hadn't been so underwhelmed by daycare choices.
I do try to tell people what it's like. Especially young people who have time to properly plan.
I always advise that they save up as much money as possible for things like babysitting/part-time nanny--how many times have we seen maxed out mommas on MDC who needed some help but didn't have family or money to hire help? Too many times. I wish I had known to save more $$$ than we did (and I have/can afford mother's helpers!).
And that the biggest indicator (imo and ime) of parent quality is how well individual parents perform under extreme sleep deprivation. If you can function on 2-3 hours of sleep for months on end, you will have the energy to be a great parent, kwim?
Then I urge everyone to get 5-6 crockpot meals down before kids. It helps to be able to dump stuff in one pot and retrieve a nice dinner 6-8 hours later.
And I tell people to ask for help. I was just talking to my 20 something cousins and advising them to just have their mom move in for the first 8 weeks, esp. if they BF and let her baby them and the baby. Then grandma needs to come back at the 6 month mark for some more TLC b/c it seems that's when the sleep deprivation really starts to hurt.
As for the emotional life of a parent...gah, I don't go into it too much. There are so many days where I feel like a failure, not just as a parent, but as a human being. DD finds my fault lines and stresses them until I do something to 'heal' them so to speak. I find myself doing a lot more personal work on myself than I thought I would.
The thing that is hard to express is the absolute takeover of your life by kids. There is just no breathing space. I routinely am running flat out for my life from 7am through midnight. Taking care of DD, cooking, working, more working, more DD--I don't even clean on a regular basis and I'm still not able to get everything done.
I basically tell this anecdote to drive the point home "I was having an anaphylactic reaction to an antibiotic and even though my throat was swelling shut and we had to call 911, I still took care of DD." I mean, even if you could die, you're still mom, kwim? I don't know that anyone gets that until they have kids.