The British won the French and Indian War, but it was a costly affair. The British naturally wanted the American colonists to help pay for it, as, from the British point of view, the colonists were the primary beneficiaries of the victory.
One way the British attempted to cover war costs was by rolling back their longstanding policy called salutary neglect. Under salutary neglect, the British had turned a blind eye to the many ways the Americans were breaking British law by trading with others nations without collecting the required tariffs. Formerly, the thinking had been the following: everybody (European, that is) is making loads of money on colonialism, so why rock the boat? Now, however, the British felt they needed that tariff revenue. The British also raised taxes, such as through the Stamp Act and through a tax on tea.
The Americans, who had been left to their own devices for so long, were outraged at what they considered British "tyranny" and taxation that interfered with their rights. If the British had left the Americans alone and born the cost of the French and the Indian War without imposing extra burdens (however light) on the colonists, arguably tensions would not have flamed up the way they did.
The end of the French and Indian War was one of the main catalysts of the American Revolution. British officials got to see how American colonists willingly flouted the Navigation Acts and dodged taxes. The war was also quite expensive, and Parliament insisted that the colonists pay their fair share.
Since the war started in North America when land speculators ventured too far into western territory, Britain passed the Proclamation Line of 1763, which barred American settlement west of the Appalachians. Land speculation was a big industry in the colonies, and the growing population demanded a never-ending supply of land. The colonists felt as though they were being denied land that they could use for both their and Britain's benefit. The colonists also felt slighted in that their contribution to British military victory was minimized. Parliament only wanted the colonists to pay taxes—this was hardly the appreciation the colonists expected. Parliament asking for the enforcement of the laws that it had not enforced before led to colonial resentment and protests. This situation would escalate into revolution in the ensuing decade.