If you're relating about the OP purchasing Pizza with $6 worth of Bitcoin through the lightning network I dont see any reason why he/she will regret it in the future. Why did i say that?
1. He/she just did an important advertisement of the Bitcoin lightning network to a business owner who will properly make the lightning network known to their countless customers.
2. Every crypto enthusiast knows that there be huge traffic in the crypto market in the next future and Laszlo Hanyecz that spent 10,000 BTC on pizza technically has thousands more and if he did do it BTC maybe not notice as a means of payment in the year 2018.