Keep it simple is great advice.

At its core property management is simple though.

In my case it was not as simple as wake up and do it.  

Plain and simple, knows his stuff.

I am the only real estate investor with my bookkeeper and at first she thought this was a little overboard but once she started setting rules in Quickbooks to simplify her work she quickly realized how simple this method makes things.

I for one built a simple chrome extension to see if the mortgage is less than rent and accordingly provide that information on every zillow listing page.

I don’t have an STR myself but have helped a friend set up and manage a couple last year and it’s not as simple as it used to be. 

Can I still do simple 4 box calculation? 

It's simple really.  

Your mentor has needs; try to meet them and develop a mutually beneficial relationship.A mentor can benefit your growth, but it's not as simple as one post on a forum full of strangers.