No OPM - What is the best approach?

[Dan Dima-ala]

I am extremely apprehensive when it comes to borrowing from, or partnering with, friends/family/acquaintances. I just can't stomach the idea. But because of my apprehension, I fear I might be missing out big time (benefits of leverage, expanding network, etc). Is it reasonable to plan for a 10-year time horizon (i.e., retire in 10 years) despite this constraint? My personal definition of retirement is basically passive income being more than expenses, so it's not an overreaching goal IMO. 

Would love to hear other investors who mainly use banks as their OPM. Thanks!