To be honest Midwest is right that in the days of the British empire we did a lot of bad stuff to other countries, but the colonialism story is at best mixed. I don't care so much for the past though apart from a curiosity, i always think what my great grandparents generation did has nothing to do with me, can't give me credit can't blame me either. We definitely are lucky to have an elevated importance in the world due to our history whether bad or good, and some times we were on the receiving end eg Roman empire. Look at what happened when they collapsed.
On the other hand look at countries like China, whatever your opinion on the big cultural differences, the Chinese were never into colonialism and were pretty far ahead for most of recorded history. Like most countries they are proud of their history even despite more recent mistakes.
They are certainly doing well as a whole for being one giant self contained country, but some sections are left behind. I've no idea how they would consider if they were given a referendum to split into provinces! i guess the squeezed or left behind people would be more inclined to vote leave?