Interviewers may well ask "Tell me how you have used the xxxx pattern." Many people want to quickly code up an example of each pattern, or find a place to force fit one into their current project. Try to avoid the temptation.

As you read about patterns, think back over code you have written and read. Have you solved similar problems? Did you come up with a similar solution or something different? Would the design in the pattern book have been better ... or not? Do you have a challenge right now that matches the intent and drivers for some pattern?