KISS (keep it simple)
First of all, when you design, solve things in the simplest way possible. Your goal should be simplicity, not “how can I apply a pattern to this problem.”
Don’t feel like you aren’t a sophisicated developer if you don’t use a pattern to solve a problem.
Other developers will appreciate and admire the simplicity of your design.
Than said, sometimes the best way to keep your design simple and flexible is to use a pattern.
from Head First Design Patterns by O’Reilly