This experiment was conducted by Psychology Professors at Stanford University and the research findings were published in 1972. They found that SELF DISCIPLINE is the most important factor for being successful in life. If cultivated and practice from young, there is a very great chance of being successful in later years. People who have self-discipline are able to resist temptation of an immediate reward and wait for a larger reward in future (delayed gratification). For example, If you delay the gratification of watching television and get your additional math homework done, then you’ll learn more and get better grades from your O Level A Math which translates to more opportunities and rewards in later years.
If you think you do not have self-discipline, well, you can learn to develop it gradually. Start very small. Tell yourself that you will spent 55 min instead of 1 hour on the computer everyday. Improve by decrease it 5 min every week. Set your final goal of maybe say 30 min after an predetermine period. Give yourself a nice reward once you have reached this goal.
You can train yourself to delay gratification by promising something small and then delivering. Over and over again until your brain says, 1) yes, it's worth it to wait and 2) yes, I have the capability to do this.