Best REI decision you've made?

[Scott Passman]

I am in the midst of finishing a book on learning to evaluate decision making. It has me curious, what is the best real estate investing decision you ever made? "Best" could mean most impactful, decision you learned the most from, most lucrative etc. I'd love to hear your experiences and, better yet, your thoughts on them.  How much could be attributed to luck vs. skillful decision making?