I’ll be turning 50 soon. Looking back, I’ve learned a lot of things. Sadly, some things, like how to do long division, or a cartwheel on a balance beam, I’ve forgotten. Others, I know I’ve learned, but can’t for the life of me explain to someone else — like how to parallel park a car or successfully clean dog poop off a toddler.

That said, in almost 50 years, I’ve learned a lot of important things that I think I should share:

Some things are almost always worth investing your time in — studying for final exams, washing a new red shirt separately, flossing. Others, not so much: watching “very special episodes” of Disney Channel tween sitcoms, or standing in a long Black Friday line at Old Navy to save what’s probably $1.50 on a pair of khakis that you’ll spill something on by mid-January.

There are certain things worth splurging on. Eyeliner, ground cinnamon, toilet paper. And others you shouldn’t bother spending a lot of money on —  birthday cards, dish towels, kids’ dress shoes. Just trust me on these; I’ve done the research for you.

Eating gross things is probably not going to hurt you. The best example is the boy I knew growing up who regularly ate red crayons in kindergarten. We’ve lost touch, but last I heard, he was a professor at an Ivy League university.  I’ve also seen people eat dog food, lip balm and White Castle. They all survived.

You will probably never forget really embarrassing things. During college, I was once at a fraternity party talking to a cute guy. I don’t remember his name or what he looked like, which of my friends I was with, or what fraternity it was. What I do remember vividly is the sight of the piece of gum I was chewing flying out of my mouth and across the room mid-sentence. In my memory, the gum moved in slow motion, and the unnamed cute guy and I both watched it sail across the room and land on the floor. I don’t remember what happened after that, but suffice it to say I’m married now, and it’s not to that cute guy from the fraternity.

You’ll probably have a few regrets, but try and learn from them. I once stress ate almost a whole of a box of Honey Bunches of Oats in one sitting. Then I threw up. And many years ago, I hastily opened a bag of M&Ms for a party. You need to be careful with those things; the bag pretty much exploded all over the kitchen. It was when I was in high school, but I wouldn’t be surprised if my parents had found an orange M&M behind their refrigerator in the last few weeks.

And then there are a few pointers that I just can’t categorize:

• A child under the age of one can’t properly digest a large amount of watermelon.
• When dishwasher directions tell you not to use dish soap, they’re not kidding.
• No matter how old you are, if the ice cream falls out of your cone onto the boardwalk, you’re going to want to cry.
• Just because the dollar store sells steak doesn’t mean you should buy it. This is just common sense, not personal experience.

You’re welcome.

I’ll be turning 50 in seven months. To be honest, it’s the first “milestone” birthday that I haven’t felt great about. On my 30th birthday, I was planning my wedding and had a job I loved. When I turned 40, I was busy with 6- and 2-year-old sons, teaching part-time and freelance writing.

And here I am now, almost 50 — still teaching part-time, still writing. My boys are in high school and middle school; they still need me, but the job of parenting has changed and requires less of my time and more trips to the gas station. My husband and I have, in recent years, often been ships passing in the night, so to speak, as we juggle jobs and parenting.

I’ve been struggling with finding a way to make this birthday meaningful. What gift could someone possibly give me that I don’t already have (except for, let’s say, better vision and a good night’s sleep)?

After seeing several ideas online, I decided to make a commitment to what I’m calling my “50 for 50 Project” — 50 random acts of kindness to celebrate my 50th birthday. I asked friends to join me with their own acts in honor of their own milestone birthdays.

I started today; one down, 49 to go. And I started simple — a handful of post-it notes with cheerful messages, left in random places. I wrote out the notes, and after being sarcastically mocked, not necessarily unexpectedly, by my teenage and almost teen son, I took them with me on a few errands.

I started at the drive-through at the bank. I planned to leave one of my happy post-its on the drawer after I completed my transaction. But I finished up and took my receipt; the teller didn’t leave her post, and seemed to be challenging me to a staring contest. I chickened out and drove away.

Next stop – the ATM at a different bank. I drove through, took my cash and smiled as I stuck a post-it to the machine. But it immediately fell off and fluttered under my car. I was still determined to brighten someone’s damn day, so I drove up, got out of my car, walked back and stuck the corner of the note into the part of the machine where the cash is dispensed. As I got back into the car, it started making a weird noise, so it’s entirely possible that rather than making someone happy, I broke the ATM.

Off to the supermarket. On the way in, I stuck one of my notes on the seat of a shopping cart. I’d planned to put a few of them on items around the store, but it was jam packed, and I knew I’d feel weird if someone saw me sticking “have a great day” notes on their cereal, so I did my shopping and left. On the way back to the car, I saw that the cart I’d gotten to earlier had been taken, so I imagined someone smiling their way through their shopping. I loaded up my car, and put another happy post-it on my cart before returning it.

I’m going to count this as a successful start, even if it didn’t go exactly as planned. I hope that at least one person found one of my notes and smiled. I hope that each subsequent random act I do will feel a little less weird, but I’m glad I’m taking some steps outside of my comfort zone. And I REALLY hope I didn’t break the ATM.