Here is a video of a guy who bought Toyota Prius back in 2013 with 1000 BTC. If you could have waited for a bit, specially in 2017, we could have been a Lambo. Although in the video you will see the Prius side by side with his Lambo so I think this guy really did make a lot of money in bitcoin in 2017 as well. He also talk about the lessons he learn from investing in bitcoin.
Well, also the guy who bought two pizzas with 10,000 bitcoin back in 2010 could have said the same thing "If I had waited 2017..."!!!
But if everyone waits for a future increase in the price of bitcoin, instead of using it to buy things, no one will ever use bitcoin and everyone will just sit and wait to gain more...