Carnival Corp. (CCL -0.58%) is no longer a meme stock. It's up 65% over the past year, and its business is back to booming. Now that it's rebounded, should investors move on the next big thing? Not so fast. Carnival has a powerful leadership position as the largest cruise operator in the world, and it might deserve a spot in your portfolio. Let's see where it could be five years from now and whether or not you should buy it. Demand for cruises is still hot Carnival demonstrated an incredible recovery last y ...