3 Rules for enjoying your puzzle solving time:
1. Never force, or deform the puzzle while solving.
2. Don't worry, take your time, it will work.
3. Most importantly: don't peek or look at the solution...
3 words of advice before you throw the towel in:
1. Never say or think your puzzle is "impossible to solve".
2. Don't get stuck on your first idea. Be careful of tactics that seem too easy or logical; those are usually the traps. Don't forget to test the least likely option. The solution usually comes from an action that seems to lead nowhere.
3. Never, never give up! A puzzle is a series of steps. You might move quickly at the beginning, and then get stuck, but eventually you'll see the light! Remember, perserverance will always lead you to the answer!
Note: the difficulty of puzzles are indicated in a subjective way. One puzzle might appear easy for certain individuals and difficult for others.
The ability to solve the puzzle is not a question of intelligence, it depends on your vision of space and three dimensions. Everyone understands these things in different manners and each puzzle focuses on a particular principle. For this reason certain puzzles are easier for certain people.
One last thing: the puzzle is not solved by simply removing the smaller piece from the larger one, you must also put it back the way you found it, which is another puzzle in itself! Your puzzle is solved when you can carry out the series of steps to solve and put the puzzle back in its original form intuitively!