I learned that kids can get cancer when Jackson was 1 year old. He'd just learned to walk. He still wore OshKosh B'gosh overalls and loved to be rocked to sleep. There was nothing that he did wrong, or was exposed to; one day, there was just a lump.

Chemo. Radiation. Surgery. Stem cell transplant. Immunotherapy. Intensive Care. Oncology. Even though it's been four and a half years since he finished treatment, some days it feels like it was yesterday.

At times, I think I was born the day Jackson was diagnosed. The world falls silent as cancer shuts out all the background noise of work stress, mortgages, that extra 10 pounds or what's on TV. It awakens a level of empathy to suffering and an awareness to what's truly important in life.

Once a cancer mom, always a cancer mom. These are 20 things I know by heart:

It is the most unnatural thing in the world to be told your child has cancer.

There's nothing you can do or say to take it away from them. There's no fixing it.

Babies can be born with cancer.

Toddlers can lie on the floor and throw a tantrum while having cancer.

Little Leaguers will miss their games because of cancer.

Teenagers can go straight from the hospital to high school graduation, then right back to the hospital.

Children can often handle higher doses of chemo than adults.

Kids can play hide-and-seek, chase each other in toy cars and build an epic Play-Doh creation, all while toting an IV pole with chemo.

Treatment straight up sucks.

I can feel a fever without even touching my child.

There's such a thing as radioactive urine. And I've changed that diaper.

Sleeping in a hospital bed with a sick child teaches you interesting life skills, like the ability to wake from a sound sleep, grab a bucket and catch vomit.

Some kids can have the opposite reactions to medications... like for instance, something that makes an adult sleepy might amp a child up. Having a toddler stuck on "fast forward" will make you bone-weary.

The first scar is always the worst. Taking that beautiful, soft baby skin and seeing it cut open is like ripping your heart out.

You realize nothing is as important anymore as getting your child well.

A mother's love knows no bounds. Not even being puked on, directly in the face.

You'll never forget the smooth, sticky feeling of a bald head against your cheek.

Every ache and pain, no matter how long your child's been in remission, will remind you that cancer can come back.

Statistics don't mean a damn thing when it comes to your child.