Challenges are what makes people's hearts beat faster with excitement and fun. Have you ever tried to race somebody on the computer? On the bike? On foot?
Challenges are what makes top executives working endless hours before resting. They live to be the best or at least better than the neighbour next door.. The competition against the clock and yourself is the ultimate form of improvement. If you compete only against others you will only be as good as they are. Not a good idea. Your own good depends on others...
If you want to try how fast you can improve when you play against yourself or an imaginary competition try beating a game using a clock time invented by you. In a car race game for example, they use ghost cars which is the exact way you played the last time. Some games allow you to set some values for yourself. Set the clock with a value much lower than the default and never think "Well it's too hard". It's not. The default value is there thanks to people like you. Remember that. See how fast you improve ONLY when you play not with the best but against the best. You will see that everything you've done so far in the game was nothing.
The same is true for business. Set a big goal for yourself and remain with it no matter what. You will see how fast you will have to work to accomplish it. You will see how many mistakes you were making and you couldn't correct them because you were working just too slow. When you are forced to work faster all your body and mind changes to keep up with the effort. Your muscles become more efficient and your brain grows stronger cells. You can confirm this information anywhere on Google. Don't you think that Google is everywhere these days?
Do the following: Try a game in the easiest level and never change it. Write down the times you get. After some weeks of playing try the same game in the hardest level. The opponents will be very fast and to keep up with them you will have to work much harder. Now see your times and see the difference. It's so easy to check the this article value!
The best game I know to do this is Rollcage Stage 2.
You should start this game in the hardest mode. Never play in the Easy. Sure you will lost most of the times and you will be frustrated but frustration is only a sign you are improving. Once you reach the ATD Challenge you will see how bad you are and what ultimate frustration is!