Joint ventures are far from "easy" to begin setting up - especially as a broker...
Deal making does get easier as you gain more experience (and confidence), but, just like riding a bike, you'll surely go through some rough spots on the road to success - and this applies to anything, really.
However, it is your attitude that will ultimately determine whether you succeed or fail. It almost has nothing to do with your skill level, your contacts, your childhood, your situation or "dumb luck".
Attitude is everything.
It clearly shows when you believe in yourself and what you stand for.
Likewise, if you approach a potential JV deal with an attitude of "I don't deserve success", or "I just can't see this happening...", then chances are, it'll fall flat.
And yes, it's obvious. People can and will read you like a book, regardless of the words you say. It will show.
For some mysterious reason, we humans have a tendency to actually be afraid of accomplishment. I've seen this in myself, and to this day I still need to consciously reject that thought pattern.
The truth is, we don't "deserve" anything (materially) by default - it's up to us to individually decide what we desire. But it seems that our "default" disposition is to merely accept whatever comes our way and deal with it as it comes - while trying to minimize confrontation whenever possible. Even if it means living in poverty, or accepting less (much less) than we desire...
In fact, I've even found myself to be relieved when a JV proposal gets rejected, or someone says "No". It's the strangest thing.
And the only way to overcome this strange fear is to face it directly. Get out of your comfort zone. Think about how much a tiny amount of "discomfort" might be worth to you in the end - if you would only pursue your dreams with a vengeance.

Note: If you find yourself "deal-hopping", or constantly skipping from one project to the next without really accomplishing anything - this is likely a matter of fear, more-so than simply "trying to succeed". Focus on each deal until it succeeds - or until it's obvious that it will not succeed, at which point you should drop it immediately.
Get rid of whatever it is in life that's really holding you back. In many cases, this is actually people that are a negative influence on you. I'm talking about the ones that continually minimize your ideas to make themselves feel better, or persistently discourage you from succeeding as a result of their failure - which they want you to become as well.
People like that have no place in your life. I made the mistake of thinking too much of what certain friends and even family members thought of me and my ideas. The reality is that, whether they knew it or not, they were actually causing me to doubt not only my dreams - but my own worth.