Well, my "if I won the lottery" fantasy only requires a few million. One by one, I'd tell my mates to come check out my new place, which turns out to be a condo at Circuit of the Americas. While we're overlooking my collection of mint-condition shitbox cars that have no reason to be preserved, I'd hand them a check for enough money to wipe out their debts and buy a house... along with a non-disclosure agreement.

Then I'd disappear for a while, taking a road trip around the country without any sort of financial or scheduling concerns. Just show up in a random city, spend a few weeks seeing all the sights at my own pace, then moving along whenever I feel like it.

Going from millions to billions, I doubt I'd deviate from that plan too much. Once I've got myself and my mates set for life, I guess I'd set the remaining 4.9 billion pounds aside for any impulse buys, like an F1 team or a couple hundred politicians.