It's not inconceivable that in the future humans will have computers sophisticated enough to simulate entire worlds full of sentient people. If so, it is not hard to imagine those future humans running a very large number of simulations of the past in order to better understand the past. If this is the case, then the number of simulated humans living in 2015 would vastly outnumber the real human beings living in 2015. Assuming that computer science continues developing at its current pace, aren't you statistically more likely to be a simulation of a human than a real human? How would you know if you were real or part of a simulation?
Of course solipsisms are absurd. That's the very nature of them. However, since we can't actually prove that reality is real, we can't really say that anything we know is 100% true even if it were possible (and I really don't think it is) for our flawed minds to grasp such a truth.
I know it's tempting to think in a binary way: everything is either completely true or completely false. After all, every single thing our teachers ever asked us to understand was treated as being absolutely true or absolutely false. However, our teachers had to deal with facts this way because they had to plow through a large amount of material in a short amount of time. Here in the real world, we have no choice but to accept that every idea we have is on a sliding scale between "almost certainly true" to "definitely false" and everything in between.
Aside: on the topic of solipsism, it's entirely possible that our entire universe is a 4-dimensional projection of a 2-dimensional surface of the event horizon of a black hole in another universe. If so, then reality definitely isn't what you think it is.