Grouping Europe (or America) together as one can be corrupt in some situations, but I don't believe it is accurate to mention the entire of Europe when talking about colonisation. There is a big part of the continent of Europe that never had anything to do with colonisation. https://en.wikipedia.org/wiki/List_of_colonies

You are right that Europeans and American's are very similar in some areas, for one that might have to do with the fore mentioned colonisation of America. Heck America has been doing a digital take over of the world, which Europeans are just (or a couple years ago) realising it is in our best interest ot create our own alternatives.

But there are tons of differences as well, for one, that America is a country and Europe is a continent. Which isn't even all united. The EU only has 27 states and a couple that want to be, while Europe has 51 countries. That is not that important when talking about culture, to be fair. You can see a lot of cultural differences when looking into company culture, work ethics, how people pay, sharing meals/receipts or things like sports, but also on the sense of the military and how nationalistic people are. All of the above are also different between different European countries, some might have similar things regarding sports or things that are centrally arranged like payment methods/platforms, but others are vastly different between countries. The Fresh are generally a very nationalistic people, while the Dutch are more or less the opposite.

Edit: where are you from?