Yes but factor in things like children; in the UK it costs around 150k to raise a child to 18 years old based on minimum acceptable housing/care, given that in reality children are financially dependant on parents into their late 20's in many cases these days, it's not unfair to say at least 500k could go on raising a couple of kids to adulthood. It costs on average a family of 4 in the more reasonable parts of the UK 25k/year in living expenses, so that could set you back another 500k+ (assuming some costs are already factored in to the cost of raising the children, and they leave home taking expenses down to 2 after 20 odd years).
Also consider that, whilst in theory it's 'easy' to get richer when rich, in reality people who come into large windfalls of money very often make extremely poor use of it. The amount of sports stars going bust after retirement is staggering, in the US a lottery winner is more likely to go broke within 3-5 years of winning than the average american, 1/3 of lottery winners declare bankruptcy etc. As much money as 2m is, it's amazing how quickly it can go. I'd hazard a guess and say a higher % of people with a 2m windfall end up worse off in the long run than the average civilian than better (just a complete guess/opinion).