We often hear about the importance of lifting and the benefits it provides: strength of body and mind. Doing a simple routine consisting of just the 'slow' compound lifts will certainly make you stronger and more confident and you don't need to perform olympic lifts to gain strength. However, anyone that performs the olympic lifts will know that the psychological benefits of the weightlifting are unparalleled by the squat, deadlift, and presses. (If you're unfamiliar with the Snatch and Clean&Jerk, familiarize yourself with some of the greats doing them on youtube.)

Here is why the olympic lifts are so important and beneficial for your mindset and frame.

*Weightlifting is hard. Pulling a max deadlift or doing a heavy set of squats demands strength and willpower, no doubt. But even these are not as demanding as a heavy clean and jerk, where one has to pull hundreds of pounds from the floor, throw it into the air and catch it, perform a near maximum front squat, and then throw the bar overhead while diving under it, all in a matter of a seconds. No lift will push you to your limits like the Clean and Jerk.

*Weightlifting requires incredible focus. You always go heavy with the olympic lifts and to succeed everything must be executed close to perfectly. You must use all of your power, place the bar immaculately, and always retain precise balance. Doing this consistently, while tired and with huge loads, demands the utmost mental focus. Any hint of not making it in your mind will make you miss the lift.

*You will be scared. Throwing yourself under hundreds of pounds in a fraction of a second is terrifying. Your body knows this and always harbors a subconscious fear of dropping under the weight to catch it. On top of that, everyone in the gym is watching you. You will be scared. And to succeed, you will learn to overcome it.

*You will learn to commit. Going hand in hand with overcoming fear, you will learn to face it and commit 100%, acknowledging the risks and boldly forcing yourself to succeed despite them. This skill will manifest everywhere in your life.

*Most important of all: You will fail. Sure, you can fail in the slow lifts. But these failures are unordinary and of lesser magnitude. Pushing your boundaries in olympic lifting will necessitate lots of failure. You will learn how to fail, over and over, and press on to lift more weight than you ever could before.

Edit: I'm echoing some of the replies below. Learning the olympic lifts properly is crucial. It's not something you walk into casually, but it is worth the time it takes to learn properly. Coaches are helpful.