Although in real life we can see and experience suffering around us at any given time, we tend to easily forget what we have witnessed. As a result, the miseries we so witnessed cannot help us discern the true nature of samsara. This is why the Buddha taught us to regard samsara as nothing but suffering.

Some people may disagree and ask, “How can samsara be full of suffering when we have actually experienced happiness in this world?” But this feeling of happiness is really the result of us being obscured by some superficial and transitory appearances. Once we realize the truth behind the so-called happiness, we may begin to feel quite anxious about the precarious condition to which this life has been taking us so far.

- Quote from The Right View, "The Four Noble Truths—the Path Out of Samsara"