I don't recall where I heard that. Perhaps my high school guidance counselor. Maybe my parents. Could have been one of my college advisers. Regardless, it's definitely a very good quote, and should be some serious words to live by, for everyone.
Right now - I love what I do. L. O. V. E. LOVE it. I spend my days sitting in my home studio, creating action figures of characters that I love from film and comic books. Sometimes I get commissions for characters I've never heard of, so it expands my library of information. Sometimes, I just get a crazy idea for an original character. Sometimes I just sit and sift through books (and books... and books...) of reference material getting ideas for something to make. But whatever I'm working on, it's not 'work'.
Sure, I get paid to do it. But it's not 'work' for me. It's a labor of love. I know that sounds corny, but it's true in every sense of the word. There are days that I step into my workshop at 8am, and before I know it, my wife is calling me to come upstairs because she's going to sleep and it's 11pm. Sure, I stop for lunch and dinner, and maybe an extra drink here and there, but... I just get lost in what I'm doing, and time passes without me even registering it half the time. When was the last time you stayed in your office or job for 14+ hours because you wanted to? Because you were enjoying it?
Over the years, I've had several jobs. And some of them were jobs that I thought I wanted to do. Right out of high school, I got a job working in the World Trade Center. I lived in Hoboken, NJ, just a quick 20 minute PATH train ride across the river. I was just a messenger, but the job was good. It was fun. I would spend almost the entire day traveling around NYC delivering mail to our sister offices. Along the way, I would 'find time' to stop at comic shops, record shops, and the like, so it was a fun job to do. Then, they 'promoted' me to the print shop, where I would sit in the shop all day, printing up thousands of pages of meeting notes from each day's business meetings. BORING.
After that I did several retail jobs, bouncing from one store to another. Never really loved any of those, but they paid the bills.
Then, I discovered the INTERNET and decided that I wanted to do that. I'd always been interested in art, drawing, and was already halfway decent with Photoshop so I went to school and got 'certified' as a New Media Designer.
Took a while to find a job where I could put those skills to work, probably because the market was so over-saturated with 'designers'. But I did, eventually, land a job. Pay was good. Job was good... at first. Then, the commute started to take it's toll on me. Almost an hour each way, down the turnpike. Gas prices were rising, toll costs were rising, and my boss turned out to be a crazy person who worked crazy hours and thought everyone else should too, even though they weren't getting paid for it... now that I think about it, she probably just loved her job as much as I do now, because it was almost the same way with her. She would be at her desk when I got there in the morning, and she would be at her desk when I left... for all I know, she may have actually lived at that office...
But I digress.
Back on point - find out what you love to do. What you enjoy doing with your time. What makes the hours fly past, and makes you never feel like you need to watch the clock so you can get the hell out of there. Discover what does that for you, and then figure out a way to get paid doing it. And do it. You won't regret it.