Planning with future gambling wins is like counting your chicks when the hen have not even hatched the eggs. Gambling is unpredictable so planning with it would make your plan of actions to depend on probability. If your friend achieved all he planned this year through gambling, then he is just lucky this year because he maybe might not accomplish such feat next year because of the unpredictable nature of gambling. It might also be possible that he is not speaking the truth.

Planning with gambling wins can cause frustration and even sicknesses if the plans fail to materialize. Lets just say that you are planning to renew your yearly house rent with your next month's win and you lost most of your games. You might become frustrated because it might lead to homelessness.