What's your biggest mess up?

[Ru Schaefferkoetter]

It's embarrassing to say it loud here -- I MESSED UP my very first investment, took a big loss, and still trying to get rid of it. Sparing y'all the painful stories, here are my biggest learnings. 

Lesson # 1: NEVER EVER, EVER buy a property out of state without having seeing it, no matter how good of a deal it seems. That's how I ended up with a house with drug-dealing squatters, then a "swimming pool" in the basement.

Lesson # 2: Invest in finding good people. My piece of junk ended up brought me to the city, lead me to meet some great contractors, neighbors, and future partners. Call it a silver lining, but I could have done it BEFORE throwing thousands of dollars away.

Lesson # 3: don't just rely on data about a city, run the research STREET by STREET! Googling "best cities to invest" did me no good, as I learned that each neighborhood, even each street, can make such a difference. I was being lazy and got my butt kicked.

BP folks, I am sure it is not all rainbows and unicorns in your journey, and I am sure you have to overcome hardships and mistakes. Could you share a bit about your biggest learnings?