I think the imagination is important..."merely imagine yourself to have been on the brink of being."...is an important thing too. Helps keep your motivation when everyone else thinks you're crazy, and only you can see the path. That's what you need sometimes--you need to be the only person who can see the path, because that's sometimes what you will be. Nobody in the people you talk to or know will be able to support your belief in this...because to their perspective, it's not viable. That's the difference between you and them. One difference. The ability to keep going. So it's not "merely imagining", the imagination is all important. It looms over everything else, and guides. That and your emotions, what you really want. To take you there, that's the only motivation you can really count on: imagination and emotion. Otherwise you won't make it. You'll give up. That's what I think...so those things, imagination and emotion are to be cherished and protected. Like PG's "embryonic" startups, or anyone who knows the feeling of trying to protect a fragile little flame of a thing (an idea, a being, whatever), before it's ready to take on the world without such nurturing protection.

So as well as tempering yourself with reality...which hopefully some of the points above may assist with--you got to keep the flame alive. Be the keeper of the flame. Of your own dream. That's what you need to succeed, one ingredient.

I think without the imagination and emotion emphasis, focusing just on the "reality" and statistical aspects is too dour. Good luck! Whatever you choose to do, good luck !