As I was rocking my 4-month-old this morning—bouncing and shushing and trying to get her down for her nap—I was overcome with a flood of emotions. She was smiling at me, her eyes full of love and magic and wonder, falling deeper and deeper into sleep as her eyelashes fluttered and her smiled faded.

It has been a hectic morning. My 4-year-old was home sick again from school for what seems like the 500th time this year.

My babysitter's child is sick, too, so I had my 2-year-old with me at home. She has been demanding to sit on my lap, wiggling around, as I try to get work done on my laptop. It's been—let's just say—causing my blood pressure to rise.

She was following me around the house as I was tending to my sick preschooler while also tending to my 4-month-old while also trying to edit and take a meeting online. I was just doing too much and was overwhelmed.

So what did I do?

I lost my patience with her. At her. I told her to stop whining. All the positive parenting techniques I try to incorporate into my everyday life flew right out the window.

I reflected on this (and cried) as I rocked my 4-month-old. My 2-year-old was just this little, too. I was just rocking her.

How is she now demanding Bubble Guppies instead of Daniel Tiger from me? She was just giggling at the funny noises I was making as she lay on her playmat. I was all the entertainment she needed.

How is she telling me (very sternly) "I need some space, Mommy!"? She was just happily eating up every single word I fed to her. I could get her bright eyes to shine and her smile to beam from ear to ear in a millisecond.

How is she getting so tall and growing out of her big girl shoes? She was just in nine month clothes, wasn't she?

How is she voicing her own opinions and directing me, her father, and both of her sisters on what to do and how to do it? She was just starting to babble and say 'Mama' like, a couple of weeks ago, wasn't it?

That's what I feel like. Especially when I lose my patience. Especially when guilt creeps in.

Because sometimes I forget.

I forget how young she really is. She's only two!

I forget how little she really is. She still fits perfectly in my arms.

I forget how her brain is not fully developed yet. She is really smart, but doesn't always understand my requests and directions.

I forget how she doesn't know how to process and handle all of her big emotions yet. That even though she's articulate for her age, she hasn't emotionally matured yet.

I already kind of forget how she felt in my arms, when I was rocking her at four months—so small and so helpless.

Because now she is big and can do things for herself.

When I set my third daughter down when she was deep in sleep, I felt an urgent sense of panic to go into the archives and look through old photos of my oldest two to remind myself of that time in our lives. To remember what it felt like to be a mom of one. Then a mom of two.

This morning, my moment of clarity came while rocking my baby girl. I still feel like a new, baby mom. While I'm not seasoned vet, I'm not really a "new mom." I'm a mom of four years and have a preschooler, a toddler, and a baby to prove it.

But one day my babies will all be kids, then teenagers, then adults, and I'll close the chapter of my life when I had babies. I won't be this mom anymore.

So I have to remember.

Because it's breaking my heart to think I'm forgetting.

Most days are so busy—busy with fun things, hectic things, school things, crazy things, overwhelming things. Full of beauty, love and madness.

But these are the days. THIS is what life is. My beautiful babies. My blessings. I need to remember these moments with them. Please don't let me forget.