Well, lets rephrase "your first game will fail!" to "your first project will fail!"...
Maybe the first game you finish is highly successfull... but to get there, you most probably killed project after project early after finding out that you were biting off more than you can chew. Happens to all of us, believe me. Some have the insight to kill such projects early. Some finish the project, and move on knowing what they built has only value as a learning expierience. Some will try to release their early projects, and will fail with them most probably in the market.
Which brings us to the next point: how do you define failure?
Financial failure? Unless you are a born businessman, have a lot of expierience in the games industry already, or just tons of luck, being successfull from your first try is most probably a pipe dream. You could call that a failure... or not.
Finishing a project? That is easier to achieve, still most people overscope at the beginning... some have the endurance to see through an overscoped project, spending 11 years developing them part time. Most will shelf the project at some point and move on. Again, up to definition if that counts as a failure.
I would advise you to look into "The Lean Startup" and their definition of success. In the lean methodology, everything is a success as long as you learn something from it, and apply what you learned to your next project. This of course means not investing much into your projects at first, constantly monitoring them, and killing them early when they fail to meet the milestones. Learn from it, pivot and try again. Your next project will be off to a better start for sure thanks to your new knowledge. Thus you were successfull in the sense of your failed project having increased the chances for future projects to become successfull.