I think I have a sort of answer to my question from this post. An answer that works for me.
(Obviously this is over an above the whole theological truth of sin and the fallen world.)
Why does God allow us to go through diffculties and tragedies? Some of our possible questions: Why are my parents so strict? Why did my best friend stab me in the back? Why did my loved-one have to die? Why does my life sometimes suck? Why do people spread rumours about me? Why was I mugged? Why do I have to suffer? Why, why, why? Varying degrees of "Why is this happening to me?" / "What sort of God are you?" ...... stuff.
It suddenly struck me that when God became man, he could have just had a stunning carefree life - after all he was fully God as well as fully man. But to be fully man, he had to experience life as a man.
Jesus experienced the discipline of parents, he experienced the death of friends, he experienced a close friend stabbing him in the back, he was the topic of rumours and vicious gossip, there was an attempt to bribe him with power, wealth and status, he had a close friend deny that he even knew him (3 times!), he had brothers who were not particularly stoked with who he was, he was beaten up beyond recognition, insulted, mocked and crucified. Yet, we never hear him asking "Why is this happening to me... what kind of a God are you?"
so also you share in our comfort. (2 Cor.1:3-7)
Jesus identifies with us through his life experiences.