It's usually best to disregard arguments that have words like never or always because there are so many exceptions. Daizy was 17 when we met and 20 when we married. She's still there 55 years later.
The problem for young love, especially if you're still at school, is that you really need time to get your life on track. You need to find a career -- or, at least, a way to earn a living -- you need to thinking about one day owning a home and how you can finance that and, to top it all off, you're still learning about human relationships and how they work.
It takes a lot of luck for young love to blossom and last and the odds are against it. But you don't know if you don't try.
The odds are against it lasting. You change so very much from age 15 to 30. Your emotions evolve and grow.
The people that you are at 17 or 18 are not the people you will be when you are 30.
BUT........if you both work at it and keep all that in mind, sure it can. You must also remember, all of those wonderful and great marriages are not perfect. Those marriages are great because both parties work to keep it that way - and are more than willing to do so. These folks do not mind the work because they truly love each other.
If it is your "first" love and it does not last, still be glad that you had it. It will be painful when it ends, but you learn so much and appreciate love even more when it comes along again.
Well, it's different for everyone. My first love is my best friend and we have helped each other through some very rough times in our lives. In my experience, the best love is love that has had time to grow and develop to suit the both of you.