My degree is in finance - I can calculate, NPV, IRR, ROI, ROE, COC, or EIEIO (yeah, that's from Old MacDonald ...) or any other acronym we have developed over the years to make ourselves sound smart. Financial ratios are great, setting goals and using math to define and measure those goals is great - I think it's smart to take those into consideration. The reality is you never know if an investment is good until 20 years after you make it and have the opportunity of measuring your return against the opportunities you didn't take advantage of. If all of us on here took our money 20 years ago and bought Amazon stock, we would be laughing at real estate investors as schmucks right now.
Just my opinion, but I think many people get too wrapped up in the numbers and forget to enjoy the thrill of the hunt. Searching for deals, networking with other investors, running projects, and building a portfolio that is our own little kingdom in the larger world is what I love about real estate investing. Make no mistake about it, I'm in real estate to build wealth. It has proven over the last 150 years to be a great way to build sustained wealth. With that said, the hustle and grind are fun and exciting. Don't forget to have some fun!