Yes and no. They exist as they are thought to exist, therefore, they don’t exist. Cogito ergo non sum.
Would I understand the ultimate answer if you told me what it was
How do I maximize utility?
If other beings exist then do they understand reality better than us
Why do some people consider deeply and thoroughly their own existence and others do not.
Can we make or become the highest lifeform in all universes and dimensions?
But you wouldn’t say that you are a solipsist, right? 
I would but not as an existent. Just another wavelet in a universe of waves, in a moment in relative time, and space.
That moment disappears almost near the limit whereby it appears. Solipsism is like the wavelet in that instant appearance in the ocean of energy. It’s an instant of self awareness.
That instant is cosmically, eternally infinite, as multiplied by all the instants of it’s occurances, somehow attaining unified forms of apprehension.
Without solipsism, there could not be a self realization, a consciousness. Evolving beyond the animal would prove to be groundless, hopeless, and faithless. It needs to be conscious of it’s self because, of the underlying connectedness of energy would loose motive, in the existentially creative sense.
It’s an imminent organized sense of the need to be:
the Dasein. In this basic sense, the question, to be, or not to be cannot be asked, it is not a question of existential choice, it’s Being is eternally determined,
by it’s law, it’s ‘Soul’.
That Soul is grounded in the need to adhere, to compose, the general sense of Being. (In it’s Self).
But a solipsist says that there is no reality outside of the self (the I). So he does not need any realization. He thinks, and that is already all (no realization needed).
At what point have we “overcome”?
depends if another lifeform already thought of that, say a billion years ago. 
How do I minimize the number of assumptions I use to think effectively?
Why would you need any assumptions while thinking?
Why would you need any assumptions while thinking?
All philosophers make assumptions. Good philosophers know what those assumptions are. Very good philosophers hold only assumptions that do not conflict with each other. That’s pretty basic.
I assume a godless, entirely physical universe. Many people don’t. And it affects their behavior.
I suppose - but why would you think that its true - and not just note that you are uncertain about it, instead of assume it?
I am not uncertain about it. But I cannot demonstrate it. It’s an assumption. I can use these assumptions to make arguments, which may prove subsequent claims, based in part on these assumptions. Any deductive argument (or mathematical proof) ultimately rests upon assumptions. 2 + 2 = 4 rests on assumptions as all mathematics does. Given those assumptions, and only given those assumptions, 2 + 2 = 4 is a proof. Philosophers usually seek assumptions. It’s part of what we do.
I don’t see how 2+2 = 4 rests on assumptions - can you elaborate?
there is the set of knowledge based in information, and assumption built upon that. Info are not assumptions. I would say that you minimise them by continually weeding out assumptions, by replacing them with knowledge, then building a new set of assumptions upon that. Rinse and repeat all your life as like any art or skill.
You don’t only have assumptions!
WWII - Look up a guy named Peano.