Hmmm, tough one. I love my job (95% of the time!), and I love the people I work with. My DC are still at school, so I'd want to do something to occupy my time. When they're older/grown up, I'd like to volunteer with MSF (if I won the lottery!!).
If I won tomorrow night's jackpot, I'd:
-take a little time to get things straight in my head. Speak to a financial advisor and a lawyer.
-buy a house locally (so DC can continue at their schools). I'd like a house with more space: more bathrooms, a couple of spare rooms so people can stay over comfortably. Also a nice big kitchen/diner and a utility room and pantry. Nice big garden (also properly cat-proofed to stop my cats escaping it!). Outhouse/double garage. Oh and enough space for a catio for my lovely cats. Sure, a heated indoor pool would be lovely, along with a gym (but not important). I'd make sure the house is future-proofed for myself. I've seen some lovely places around the £1-2million mark.
-put some money away for the kids (but do it so it's protected for them). I'd do that on the sly too, as I'd expect them to study and work so they understand and respect the value of a day's work.
-get a smallish camper van. I'd buy a car too.
-I'd maybe go part time with work. And I'd do more studying.
-help family and close friends out on the sly.
-be able to take the DC on overseas holidays, and be able to take the school hols off as I'd request it as unpaid leave.