I'm 5'6". Our shortest is 14hh, tallest is 16'1". I'm comfortable on either end of the spectrum as long as they have enough body for my legs. I used to do "fixing" rides on my sister's quarter pony when we were much younger and he was 13 hh even, I did feel a bit funny on him! The tallest I've ridden was a 17'2" TB/WB gelding for a friend, I had never shown hunter/jumpers & she wanted extra time & exposure put on him so I rode him in the green as grass classes. Don't think now that I'm in my 30s I would want anything that tall!!!!
Life is like a camera. Focus on what's important, Capture the good times, Develop from the negatives and if things don't work out, Take another shot.