Is this saying true?

Well, from my own experience, yes! Of course, only after you reach a certain age - i.e. maybe 16, 17. Coz. that's when you start to make your own decisions (sorta). And as an adult who's finished college and working full-time, most definitely a struggle. And I don't mean just in terms of work, but also your relationships, social life, me time, etc. You'll have good days where you accomplish something in one area of your life, but you'll struggle to think about how to make it better / take it to the next level. On bad days, you'll struggle to think about how to have better days in the near & long-term future. Even if your off-time (e.g. vacation), you'll struggle to find what is the best way to spend that time. And when you're sitting idly, the thoughts of the meaning of life will enter your mind and you'll struggle to comprehend if anything you do will make any difference. The only way a person does not struggle to survive is if he or she has attained the level of self-realization, i.e. entered the spiritual realm. Of course, I have not attained this level, which is why I can answer this question.