Which is most difficult concept in Java

Hey Guys !!!

Time for some discussion now.. comment which topic of Java/concept of Java you find most difficult ? 

Based on that I will start giving you inputs.

Important topics for Java Interviews

Well !! Certainly tricky question to answer. Frankly there is no short-cuts for success. To me, there's nothing which is important and which is not !! But throughout my 10+ years of experience, many times student need the answer of this question. So, here I go --
(Though I re-iterate this is certainly not the way to face interview )

Most important topics for Java Interview

1. Collections in Java
2. Inheritance (Abstract classes/Interfaces)
3. Data type conversions/Type casting
4. OOPs
5. Exception Handling.

Cheers !!!

Keep Calm and Learn Java... Follow my upcoming posts.