Answer: Here is a brief description I have concluded;
The gateway drug effect (alternatively, stepping-stone theory, escalation hypothesis, or progression hypothesis) is a comprehensive catchphrase for the often observed effect that the use of a psychoactive substance is coupled to an increased probability of the use of further substances. Possible causes are biological alterations in the brain due to the earlier substance exposure and similar attitudes of people who use different substances across different substances (common liability to addiction).
Explanation: Hope this helps, have a terrific day! <3 Thanks are always appreciated!
Unrealistic means not realistic, or that it probably won't happen. If you set unrealistic goals, you will get discouraged and stop doing it because you probably won't be able to.