Along with the other ways to acquire properties you mentioned such as Sub To or assumptions.It's tricky because there is a lot to flipping and acquiring real estate and financing that I'm (unintentionally) ignorant about.Lots to learn.

Your screw ups can be intentional (worse case) or unintentional (still bad), it won't matter. 

I heard from someone that they lost one in two weeks. lol It's amazing how many stories I here about people unintentionally buying these things.

A nice (and perhaps unintentional?)

The huge number of unknowledgeable, unrealistic, unethical (intentional or unintentional) and inexperienced wholesalers operating with no oversight produces problems for seller's and hurts the reputation of the real estate industry.  

@Jonathan Bowen I know it's an old post but it bares commenting since I unintentionally found this in a Google search. 

I have no idea about how to market to divorce lists but unintentionally everyone of my tenants are recently divorced moms with teenage kids.

And some good ones I may have overlooked unintentionally.

And some good ones I may have overlooked unintentionally.

Here is the definition: Negligence is unintentional but irresponsible conduct that leads to an injury.