I'm not sure if that was a joke but I wasn't talking about Erasmus at all. IMO the general problem with our discussion about immigration in the UK is that it's very broad stroke - how many benefits do they take, how many businesses do they start, how much tax do they pay etc. And so you have people saying, truthfully, things like "Immigration brings in £x million to the exchequer and create 300,000 new jobs!" or whatever. But that doesn't break it down - as Quiche mentioned above, whilst you can quite easily look at net stats, that doesn't tell you that some groups benefit whilst others are harmed. In the case of immigration, it's overwhelmingly the educated middle classes that benefit (because they get cheaper services, cheaper goods, they get to enjoy that nice Hungarian cafe for brunch, they're more likely to be able to move abroad for good work opportunities as well as being more likely to be offered them in the first place etc) where as the working classes have seen the competition for their jobs rocket, driving down wages and removing from them the few high-paid industries that remained to them (notably the trades that require some form of apprenticeship like plumbing, electricians etc) and the low-skilled jobs that were typically the reserve of uneducated young people - shops, restaurants, fast food, cafe's etc - now have so much competition from people who often are older and with more experience (but to whom working minimum wage in the UK is still better than if they'd not been able to come here) that they either can't get a job or they find that their wages hardly change because of the enormous pressures keeping them down. They're also very unlikely to find themselves getting job offers from elsewhere in the EU if they're uneducated, so that reciprocal benefit isn't actually a benefit to them.
In short, you mentioned that the more educated someone is, the more chance they are to want to remain in the EU and the implication there was kinda that the people that want to leave are dumb and don't know what's good for them. My point was that it could be that the two groups - uneducated and educated - are not affected by the EU in the same way and that this is why there's a discrepancy in their support for the EU.