You could argue that the only reality is your own reality because nobody else can experiance like you can, experiance being the operative word. But you could also argue that because most people agree on the colour blue then reality is something that effects us all whether you like it or not. You could argue that we go through this life on a preordained route from the moment we're shoved screaming into the world to the moment we pass screaming out of it or you could say that all we do is bounce from one chance encounter to another and that we are the masters of our own ship.
I think rather than question reality (For me, this is it. Take it or leave it I will make it what I can) ,question, rather; perception. What you percieve to be humour, another percieves as insult. What you percieve as a tragic waste of life in the form of starvation another percieves as population control. What you percieve to be reality is actually the product of a deranged imagination, take your pick as to whoms.
Life really, really does not make alot of sense. It shouldn't be here, and yet it is. How can we, just animals, reason and imagine; Kill and be Killed; Cruel and yet so kind; laugh, cry, shout and scream. How can we, mere specks of dust on a cosmic chess board, even think ourselves as a noble, important, race. How can billions of atoms combine in just such a way to make a strand of DNA and how does that DNA know how to make that particular protein and how can that particular protein manage to give just the right amount of Hydolase too that particular cell component and how did that cell know how to form a backbone that supports a bipedal skeleton in just such a way that it enabled a large and very complex brain to form that just so happened to allow an extremely complex processor of an infinite amount of information to work without burning too much energy that it detriments the very organism it inhabits.
Life in short is wierd and complicated and I find it's best not to try and second guess it. Somebody, somewhere must know what they are doing and they must have the brain the size of a planet and are quite probable critically depressed.