I agree, that part is difficult, especially for someone new to it. That's why I recommend other avenues of real estate investing for people completely new.
You may have mentioned this elsewhere, but what avenues would you suggest for the newbie investors?
Well, there's a number of options, and I'd hesitate to recommend one in particular without knowing a person's individual situation.
That being said, a good general one for a Mustachian looking to learn is to partner up with an experienced investor and work with them (there are a number of ways this can be achieved, with or without money, though obviously investing with money is a lot easier, and more like investing than a job). Education through experience is valuable (WAY more so than those "courses" that the "gurus" try to sell you - avoid those). Learn what they do, why, how they run the numbers, why, etc. etc.
Keep reading real estate books, forums, and blogs (especially books), and as you learn you can branch out from the experienced investor and start doing your own deals while asking for their input/advice.
It's good to have someone who knows what they're doing to help guide you at first, IMO.