Can you really be 100% sure

So Ces will laugh at me for this, because we had this convo last night, but solipsism...The dictionary defines it as: The theory that the self is the only thing that can be known and verified. So that's all well and good. I'm not saying that an extreme version of that is what I imagine the world to be like, but can anyone really be completely sure that the rest of life isn't some strange experiment/program designed especially for them. Yes, it's quite self-involved, but how do I know that any of this really exists. I suppose in that essence, I could go along with do I even exist? I'm not entirely sure that my surroundings are actually there, but I can accept life for what it is. But this is just a blurb to ponder when you have time. Be careful. Don't let it consume you, for if all of this is just some made up version of what we believe to be real, is it really worth the time and effort to worry about it? Probably not.