You have probably been told to make your way to Cuba as quickly as possible before travel from the US opens up and rampant American tourists overrun the country and gut it of its rich culture. Well, by all means, make your way to Cuba as quickly as possible, but in my humble opinion I would not worry about Americans destroying it.
One reason: it is already over run by Europeans. One town I visited was quite literally filled to capacity. More than 20 tourists slept in the park because there was not a single unoccupied bed in the city. This somehow does not phase Cuba. It remains the smoky, glowing mirage it has always been.
There are some places that excel at retaining their culture against all odds and Cuba is most definitely one of them. Cubans are quick to admit that there are many reasons not to be proud of their country, but do not let them fool you, pride runs hot in their blood, and it is this deep set—and much deserved— sense of pride that will keep Cuba Cuban for a very long time.
Do it. Go. It is easier than you think, and I promise you one night in Havana will change your standard of living; will make you demand more from life. To dodge potholes in the velvet black streets as you follow scant neon lights guiding you to your next destination, to hear the clatter of music emanating from every possible orifice of the city, to finally believe for a second you are alone and then look up in the narrow alleyways and see that every balcony is not just occupied but bursting and thriving, to see and hear and smell and feel so much life spilling out of ever shadowy corner that you simply know that to just observe is no longer an option.