Puzzles are all really easy as long as you know the tricks. Starting with the most basic 2d picture puzzles, you"d usually just start with the corner pieces. Then you"d connect all the edge pieces. Next you would start sorting the pieces based on color. Last but not least, just trial and error until you complete the puzzle. 3d puzzles like the Rubik"s Cube are much harder to solve without knowing the mechanics involved. You will take a really really really long time to solve the rubric cube for the first time if you go in blind. That is a feat that deserves serious respect.
Those really stereo typical, "You can solve a Rubik"s Cube? You must a genius/nerd." comments, are far from the truth. It"s just memorizing a long list of combos and when to use them. Those people that found the combos are definitely the true geniuses.
There are way too many puzzle variants out there and they all have their own gimmicks and quirks. Thus you"ll basically never run out of new puzzles to try.
The greatest satisfaction comes from solving a puzzle for the first time. It"s like winning/beating a game for the first time.