How wrong you are. Viral is only one piece of the pie. And if it is a one trick pony you won't get anywhere. It takes dedication, it takes effort and it takes exposure. A viral video is one of those things that gives you that, but a fellow YouTuber with a big following or a website that shares your video is just as helpful. If your viral video has nothing to do with your regular content you will not gain any subscribers from it. Casey Neistat recently talked about his $21,000 dollar plane seat video going viral. But if you check out his channel all of his videos have the same production value, and most of his videos break 1,000,000 views. If you have that same viral video but have content with 300 views you aren't inspiring anyone. They will watch that video, and then move along. He gained more subscribers because all of his content is of the same caliber.
Go for gold, produce the heck out of EVERY one of your videos. Perhaps you'll make it big, perhaps you'll be at 3.5K subscribers and 650K lifetime views after 3 years like yours truly. All that matter is that you are having fun, and the people that watch your content and comment on it are having fun too.