You couldn't very well suddenly be driving around in a Rolls Royce or be wearing top clothes..people would get suspicious!
If you disappeared for a month or so..every 3 months and came back with a suntan people would get suspicious!...and graspy!

Your new girlfriend is a supermodel with breasts like space hoppers when previously...1 day prior your win..she was far from a supermodel..how wouldn't people realize that you jad come into some serious wedge?

Wouldn't it be frustrating to have to pretend to live your old life in order to keep your good (and massive) fortune a secret?

I will move to another country... Tell friends and family that I'm immigrating.

I'd buy a yacht and live in the Monaco harbour. Won't tell anyone.

Or just stay as I currently am and continue that lifestyle till I die. Will buy a mansion near my family home and live there by myself. I'd obviously tell my family why I moved and I'm sure they'll be okay with that. I don't think they'd want my money. At the mansion I'd employ a gardener maybe every third week and a maid twice a week. Will have a koi pond in the garden but no dogs or cats. Will make sure my money lasts me till I die. In fact that's better than living on a yacht at the Monaco harbor. That will last for maybe 20 years max and I'll be broke afterwards. You need to play it smart.

I'd definitely move but not to somewhere ostentatious, I would invest a big chunk in property building and leave very little remaining after the usual taking care of the family etc.

I'd move to Spain or Monaco or something.

Well now we know who'd hide it...

I'd quite simply not tell any lover and get absolutely messy all over the world. then leave what little that's left I'd leave to animal charities