That's kind of how I look at it, in practice. I get the mathematical reality that buying lotto tickets is a financial waste. However, if I never buy a single ticket, there is a definite 0% chance I'll ever win the big prize. Whereas if I play at all, at least there's a chance, however remote, of a quite life-changing positive event happening. So, therefore, it makes sense to put a very small amount of totally throw-away income into big-prize lotto tickets, just so you're in the game at all.

Based on this kind of thinking, my personal rules are: never spend more than 0.1% of take-home pay per time-period buying tickets, and only buy big-prize lotto tickets that have potentially-life-changing payouts.