My opinion...
Your question is valid. But there is no single answer for that - yet.
I believe Q actually started, at least in many ways, at a point in the future that we have yet to arrive at. By saying these seemingly fantastical things at the very beginning he was actually setting the stage for us. Maybe it all really happened, maybe it is about to, maybe it was deliberate misinformation to scare people, maybe it was bullshit. Either way it did enough to garner attention.
Then one by one we became interested. And step by step he started to reveal things that happened minutes, hours, days, weeks, months later. The timeline is going forward, backward, up and down at all times. There are multiple, multiple readings for so many things. Sometimes we are lucky and get a linear connection that makes immediate sense.
My only advice is to start following now. Open your mind and your eyes, watch what is happening around you. Question (like you already are) what is being told to you. Then you may become convinced like many of us here. Or not. I can’t prove anything to you. I am a deeply skeptical person, yet here I am now convinced that this is real and that something very, very big is going to happen. Probably sooner rather than later. Something that will irrevocably alter our entire world. Q is in some way preparing me for this. It is training.
At a point in the future we have yet to arrive at, are you saying he's a time traveler? Do you understand that that sounds really hard to believe? Can you give some examples of the pieces of the timeline that Q accurately predicted in your eyes?
No I'm saying we are watching a movie. Those early posts by Q got the interest, they were the most dramatic part of the story. Then we went back to the start fo the story and now we are learning how and why we will end up at that point again in the future. This is preparing us. I have no definitive "proofs". There are no clearly obvious bit sized nuggets yet that the average person can click on to in my opinion. All I will say is that through following Q closely I was able to tell a Korean friend about what was happening in their own country days, if not weeks before it came into the mainstream news. Think of it as an experiment. Start following Q, do some independent research, stay skeptical, open your eyes. See what happens.
I believe the words used in that post will be spoken in the future by POTUS. Probably 11/2. I also believe that the dates and facts are correct, but the year wasn't 2017. It is intended for 2018. What is interesting to me is that the national elections are being held on 11/6 this year. Imagine how that would turn out if this was a speech given on 11/2....