While it's nice to fantasize about a huge windfall changing your life, I think there are several factors that would dampen its effects:
70% of all lottery winners spend it all and more, ending up broke within a few years. Most people live paycheque to paycheque, spending whatever they make. This applies to all income-levels earners, not just those at the poverty level. Some of the higest-earners fall victim to "lifestyle creep", ratcheting up their spending to match or even outpace their increased earning power.
They never developed good savings habits, so winning a lottery would just be another (rather large) paycheque to spend. I'd bet that the 30% who did have good money management skills are the ones that were able to keep or even grow their winnings over time.
The average income to "buy happiness" is betweeen $60-$75K. If the idea is to put a number on a "life-changing" windfall, it might be a lot lower than you think.
If you've got the basics covered off, food and shelter, etc., there's a point that your underlying pre-disposition to happiness would re-emerge no matter how much *more* money you had. This is called
"hedonic adaptation".
If you're generally a miserable SOB who is unsatisfied with having to shop at Food Basics instead of Pusateri's, no amount of money will change that. You'll just be a rich and miserable SOB who is still unsatisfied with how slow the service is at the Michelin-rated restaurant you're dining at.
Not to get all "universe being a manifestation of vibrational energy" and all, but I think "life changing wealth" is cultivating meaningful relationships with the people around you, and focusing on being happy with what you do have instead of being unhappy with what you don't have.