Disclaimer: not saying people who aren't successful are lazy, but just want to provide a personal anecdotal example.

For me personally, I had to put pressure on myself to not just relax all the time. For example, life in America tries to teach you that we need to value relaxing, pampering, watching TV, gaming, napping, etc when we're not working. And honestly, I also believe those are things that should be valued. I also came from a family that all we did watch watch TV CONSTANTLY (so I really enjoy it). At the same time, I believe those sometimes can only be enjoyed in certain seasons of life. For example, when I went back to school for my masters degree I had to give up most of that in order to have the time and stamina to finish the work and get the degree. Truth be told, I only had time for work and school, work and school (I also have kids so it made it slightly harder). It's very easy to get in the habit of saying "I'll just watch this one episode" and before you know it, the night is over. You sometimes have to be your own drill sergeant and know that future you is going to want to come back and kick the ass of past you if you don't get your shit together, make a little temporary personal sacrifice and meet a goal. Also, always reward yourself once you make that goal. Study for weeks without getting to relax? Binge play games or TV after the exam is over. My point is if you're always indulging in leisure, you can't be confused when nothing happens because you didn't put in any work.