People sometimes make bad decisions in life and you have to decide whether it is forgivable or not.

Edit: And taking 10-20% equity on a deal like this with an experienced investor might be completely worthwhile and life changing to be clear. 

Some people just don't have good mentors in there life, and/or need to learn through mistake.

It's one of those things that you just have to keep on keepin on because at the end of the day, it only takes one seller to change your life.

2-4 paid off properties in great areas with minimal headache is likely life changing for most people who don't overspend monthly. 

At the end of the day, that is life however to Stuart's point, you may want to consider investing in better areas where this does not occur normally if this is an unsettling occurance for you. 

Hate me all you want, but it's my business and my money, so sell me for what I want to pay or have a nice life!

Ask anyone with investment property and they'll tell you it's not passive.I earn enough from investments that I could be financially free for life, assuming nothing major happens.

Here are a few I recommend: "Rich Dad, Poor Dad" by Roberto Kiyosaki; "Set for Life" by Scott Trench; "The Unofficial Guide to Real Estate Investing" by Spencer; "The BiggerPockets Ultimate Beginners Guide" found here on BP; "The Book on Rental Property Investing" by Brandon Tuner.

It creates a lot of friction with other tenants and normally creates a poor work life balance for the manager.