I paid $71.20 for 13.1 miles of pain and it was the best purchase I ever made

I've written about my frugality in the past - how I learned the difference between a want and a need at a very young age when I tried to order chocolate milk at a local restaurant rather than asking for (free) water.

That lesson stuck with me, and became fully integrated into my philosophy on budgeting, which boils down to one sentence: Don't spend money, take advantage of freebies, and recognize the difference between needs and wants.

So when my editor asked our team to write about the best money we ever spent, I hit a major roadblock.

In the small amount of time I've spent in the real world since I graduated from college in 2014, I haven't purchased much else than instant oats, toothpaste, and Trader Joe's wine.

My most recent "splurges" have been an umbrella for the moody New York City weather and a pint of Ben and Jerry's Phish Food to cope with UNC basketball disappointment, neither of which seemed interesting enough to write about.

After sorting through the Excel spreadsheet on my computer that details my daily expenses, I stumbled upon a highly controversial purchase from September - a $71.20 half-marathon entry fee.

It seemed ridiculous at the time to spend over $70 on a such a physically painful experience, but it ended up being the best money I've ever spent, because it made me happy, in an unexpected way.

The actual race - the grueling 104 minutes - did not make me happy. My legs were screaming, my mind was confused, and my eardrums were bruised from maxed-out headphones.

What made me happy, and brought a sense of fulfillment that far outweighed the noodle legs and cloudy mind, was the entire process that started when I decided to enter my credit card information and say goodbye to a chunk of my savings account - the process of setting a goal, devising a training plan, and tackling that plan to achieve the goal.

Completing a half-marathon is not easy. It is a challenging task that requires dedication to a training schedule, mental fortitude, and the willingness to accept and embrace pain. The moment of goal attainment - the exact second I crossed the finish line - did not provide me instantaneous happiness, but striving to achieve that goal brought satisfaction and gratification.

I gained more than an exhilarating experience, fond memories, and free post-race snacks that cut October's grocery bill in half; I learned the concept of quality spending. I learned that it is OK to spend on good things - on experiences that will make you happy.

Quality spending still makes me cringe on occasion, but I am becoming more and more comfortable with my amended budgeting philosophy: take advantage of freebies, recognize the difference between needs and wants, and spend money on good things.

Read about the best money successful people ever spent in Business Insider's Success Series.