My sister Meg had kids first. She had two before I even had one. I was next and I had three before my next sister had one.

When Meg was the only one with kids, none of us got it (we have two other siblings, too). We were just going about living our lives, going out with our friends, taking trips—doing whatever we wanted—as my sister and brother-in-law were navigating the waters of new parenthood.

I remember I was on a girl’s weekend yucking it up in NYC the weekend my nephew was born. I was prepared to head back up to Massachusetts if he made his debut, but he didn’t show up until a few days later. So there in the early September heat, I was traipsing around Manhattan with my college friends while my sister inched toward contractions and birthing her baby boy.

I didn’t get it AT ALL. Like, not even close. I did not get it until I was on all fours in the hospital trying to relieve the pressure of back labor as I breathed (winced?) through each contraction of my own.

Now that I’m thinking back on it, I really had no clue about these 10 things:

1. How absolutely amazing, but definitely grueling pregnancy can be

I did not realize how many checkup appointments you have to go to. I did not realize how heavy a baby could actually feel inside you. I did not know the lower back pain, the sleepless nights spent wishing you could sleep on your stomach, the hormonal migraines, the first-trimester hit-by-a-bus exhaustion, the heartburn, the swelling….. The list could go on and on.

And I definitely could not comprehend how incredible it is to feel your baby kick inside of you. Or to hear your baby’s heartbeat for the first time. Or to find out the sex of your baby. Or how close pregnancy can make you and your partner feel. Or how awesome it would be to not worry about any extra softness in your stomach area because of that gorgeous baby bump.

2. How life-changing the transformation to ‘mother’ is

My sister went through this complete shift in her identity—right in front of me, without me having hardly a clue. She was learning how to be a mom as I was popping over to cuddle my nephew for a bit then heading out to meet friends for dinner or a movie.

I didn’t know she was basically experiencing an identity crisis—and who knows, maybe she didn’t even know that at the time either—until I experienced my own shortly after becoming a mother.

I could never know what that felt like. And I could never understand what the moment you come face-to-face with your child—that deep and immediate love—feels like, no matter how many times she described it to me.

3. How long “having a baby” actually can take

We arrived at the hospital a mere few hours after my sister got there and we waited there for hours! I am laughing thinking about it. I basically thought she’d get to the hospital, pop the baby out and be ready for visitors. It took a lot longer than I ever thought.

4. How different birth can go than what you picture

My sister had to be induced because her son was super cozy in her womb and didn’t want to come out. Her birth went differently than she thought it would. I didn’t know that was a thing. I just thought you gave birth how you wanted to—oblivious to all the complications or changes that could come along the way.

5. How tired a mother could actually be

“You’re exhausted? Yeah me too, I was up till like 3 am watching TV.” Okay, I hope I never actually said his to her, but… I probably did. I absolutely 100% did not know what true exhaustion meant no matter how many all-nighters I pulled in college, no matter how many times I stayed up late into the wee hours of the morning (by my own choice, mind you). I did not understand the physical exhaustion of feeding another human from my body at all hours of the day and night or the mental exhaustion of worrying and remembering and doing.

6. How much effort goes into breastfeeding

Again. This is something I thought you just did. That just clicked. That just happened. I had no idea there were any smoke and mirrors in the background, like lactation counselors, nipple shields, breast pumps, supplementing, different kinds of formula, donor milk, or gastronomy tubes. I was so clueless! Imagine my surprise when I started breastfeeding 2.5 years later…

7. How strategic road trips become

Our parents live on Long Island and my sister and I live in Massachusetts with our families. I never got why they couldn’t just hop in the car to go visit my parents with us for a weekend on a whim.

I didn’t know that babies might not like riding in the car or they may get sick of sitting in their car seat after four hours or how annoying going off-routine for the weekend could be, how painful skipping naps is, how tricky it is to get babies to sleep at night in a place other than their home. I definitely didn’t even think about all the stuff you had to schlep back and forth.

8. How tricky it can be to have a baby at a wedding

When I got married, my nephew had just turned one a week prior. They were all in the wedding. In fact, my sister was the maid of honor. I didn’t know how stressful it could be to try to align your baby’s idea of a timeline for the day with the planned wedding timelineNo, honey, you can’t eat right now—it’s time to take pictures. No, baby, I can’t rock you for your nap, it’s time to get my hair done.

I actually didn’t fully realize what that felt like until I was on a plane heading to Vegas for my sister’s destination wedding with a 2-year-old and a 3-month-old many years later. #Goodtimes

9. How much support you need

I knew we all needed to be there for my sister. I knew she could use some help with holding my nephew as she got stuff done around the house. But I didn’t think to put a load of laundry on while I was over or think to randomly bring her a meal so she didn’t have to cook dinner.

I didn’t get the importance of connecting with other moms and couldn’t properly commiserate with her when she talked about how she wished she could find some mom friends. I didn’t know motherhood could be lonely—not with a cute baby around all day, right?!

10. How long it takes to find yourself again

I thought perhaps becoming a mother meant that you finally became your true self. I didn’t know that you needed time to reconnect with your core identity and revamp what is important to you, where your passions lie. I didn’t know that “mother” wasn’t just simply another hat to wear, like the “daughter” hat or “friend” hat. I didn’t know she was embarking on this giant soul-searching adventure.

I now have three kids. I get it. In fact, I get it more and more each day I learn how to be a mom. I learn more with each new challenge, each new lesson and each new #momwin.

I think we’ll all always be learning. And now? Now I not only have my older sister but I have one of my younger sisters learning alongside me too. And it has been an honor having them to walk with on this wild journey called motherhood.