Not tell a soul, and then do good with it. (Of course, this is all on the basis that I would win big on the lottery – millions, and not just a small amount).
The problem with people acquiring money is that others perceptions of them change. Fake friends come out of the woodwork looking to scrounge and sponge off them. Others would expect things of you – ie. if their car has broken down, they’d hope you’d pay for a new one because you’re now rich. You would become the object of people’s affections for the wrong reasons. You would no longer be you. You would be the richer version of yourself – with all the labels that accompany it. Thus, I would not tell a single human being, unless absolutely necessary (ie. accountant).
I would invest it practically – buy myself a house in cash, so I wouldn’t have to pay a mortgage. Equip said house with furniture and decorate to my tastes. I’d buy a new car outright, so I wouldn’t have to pay to loan or lease one. I would invest money into my pension. I would set up a trust/inheritance for any future children I may have. I would also set my parents up for the rest of their lives so they would not have to worry about their pensions.
It is only the people who truly care for you, for whom you truly care for, to which money would not make a difference – you would still be the same person you were before. It is to these people whom I would give a fair portion – my family and true friends… enough to make sure they’re comfortable and can afford some luxuries.
After that, I’d jet off and see the world for a few months – Canada, USA, Japan, Thailand, Australia… all of the expensive places. I would take my parents with me, of course.
I would give another good portion to charity – Cancer Research, the Alzheimer’s Society, and any others I may feel I need to make a donation to.
Then, I would open the bookshop/cafe I have always dreamed about owning – chic and classy, and full of hopes.
The remaining money (if there was any left), I’d keep for a rainy day.
And, after all that, I’d go back to work like normal. Just another day at the office.