Physical Pain & mental frustration is there, but concealed by the hope for pleasure:

Buddha once said: Dukkhānupassanam bhāvento sukhasaññam pajahati...

When developing the contemplation of Suffering (dukkha), one gradually overcomes the false perception of pleasure...

If there were no satisfaction to be found in the world, beings would not be attached to the world ....
If there were no misery to be found in the world, beings would not be repelled by the world ....
If there were no escape from the world, beings could not escape from this world ....

AN 111, 102

The stage of Viewing:
Each time one changes posture of the body, one should note, that this was caused by bodily pain...
Each time one changes plan or search, one should know, that this was caused by mental frustration...
Every time one has headache, toothache, any illness or sickness, one should see: Painful is any body...
Every time one is disappointed, separated, or depressed, then one should note: Any mind incurs grief...
To see & realize everyday misery, by not dismissing or neglecting it, is a very advantageous teacher!

The stage of Comprehending:
Having seen & realized that both bodily & mental pain afflict us every minute, one may understand, that this 'obvious pain' & suffering (dukkha-dukkha) is a common & inevitable part of any existence..
When the body decays & grows old, & when the momentary pleasure, joy or happiness fades away, one may realize the rise & inevitable fall of all conditioned constructions and thereby comprehend that suffering is an unambiguous part of any conditioned formation...
This more hidden suffering is called 'suffering due to constructedness' (sankhara-dukkha):
All constructions will fall apart...
Finally, there is the fact of impermanence, which implies, that all found forms of worldly joy, satisfaction, pleasure and whatever kind of happiness, will never last and thus quickly be lost...
This causes a frustration, which is called 'suffering due to change' (viparināma-dukkha)...
Gradually comprehending the abundance of these 3 kinds of suffering makes one realize:
All phenomena - even pleasant feeling - are nothing, but one massed up heap of suffering!!!

The stage of Gaining Insight:
This ultra realism squeezes one out of the cocoon quite well camouflaged by common comfort...
The knowledge of inevitable Dissolution of all phenomena and states arises (bhanga-ñāna)!The knowledge of any appearance is a true Terror arises (bhayatupatthāna-ñāna)!
The knowledge of the Danger inherent in any form of dependent existence arises (ādinava-ñāna)!
The knowledge of the Disgust with all things & states in any world arises (nibbidā-ñāna)!

The result of contemplating
Suffering is absence of mental distortion (vipallāsa):
Direct and repeated experience of such disgust gradually detaches mind from it's habitual attachments by disclosing the universal defect of all these deeply cherished objects:
No form, feeling, perception, mental construction or kind of consciousness will ever last!
This violent revulsion break the misconception that the 5 clusters of clinging is a sourceof true and lasting pleasure and happiness.
This mistaken notion leads otherwise to thehedonist distortion of perception (sañña-vipallāsa), distortion of thinking (citta-vipallāsa), and distortion of view (ditthi-vipallāsa), which makes one perceive, think and claim the view:
"This world, this life, all formations & all phenomena are essentially pleasurable!"...
Such distortion makes one run after fleeting pleasure & evanescent happiness in a transientworld, as the thirsty & scorched man runs in hot pursuit for a water mirage fata morgana in the completely dry desert...
Seeing, comprehending and fully understanding this abysmal futility redirects mind towards the deathless, safe, and lasting peace of Nibbāna...