we are under a spell

 The foolish cannot understand how a living entity can quit his body, nor can they understand what sort of body he enjoys under the spell of the modes of nature. But one whose eyes are trained in knowledge can see all this.

utkrāmantaṁ sthitaṁ vāpi
bhuñjānaṁ vā guṇānvitam
vimūḍhā nānupaśyanti
paśyanti jñāna-cakṣuṣaḥ

Synonyms

utkrāmantam — quitting the body; sthitam — situated in the body; vā api — either; bhuñjānam — enjoying; vā — or; guṇa-anvitam — under the spell of the modes of material nature; vimūḍhāḥ — foolish persons; na — never; anupaśyanti — can see; paśyanti — can see; jñāna-cakṣuṣaḥ — those who have the eyes of knowledge.

Utkraamantam vs bhunjaanam, Vimudha vs Jnana cakshusah, a word, phrase, or form of words supposed to have magic power; charm; incantation: The wizard cast a spell. a state or period of enchantment: She was under a spell. any dominating or irresistible influence; fascination: the spell of fine music

The word jñāna-cakṣuṣaḥ is very significant.

Without knowledge, one cannot understand how a living entity leaves his present body, nor what form of body he is going to take in the next life, nor even why he is living in a particular type of body

leaving(present), going to take(future) and why this body(present) -> these 3 cannot be understood

This requires a great amount of knowledge understood from Bhagavad-gītā and similar literatures heard from a bona fide spiritual master.

One who is trained to perceive all these things is fortunate

Every living entity is quitting his body under certain circumstances, he is living under certain circumstances, and he is enjoying under certain circumstances under the spell of material nature

As a result, he is suffering different kinds of happiness and distress, under the illusion of sense enjoyment.

The modes of material nature cast a spell and pushes to embrace false identity and false enjoyment. Hari trpti karya is the only way to come out of this spell. Spell can lead to forgetfullness. Are you under the spell - everyone is under the spell of mayadevi; 

Persons who are everlastingly fooled by lust and desire lose all power to understand their change of body and their stay in a particular body

They cannot comprehend it. Those who have developed spiritual knowledge, however, can see that the spirit is different from the body and is changing its body and enjoying in different ways.

A person in such knowledge can understand how the conditioned living entity is suffering in this material existence

Its not about career, money fame etc....its about coming out of the spell. world is full of struggle(karsati) and miseries(dukhalaya). Drop the desire to be happy in this platform by Jnana cakshu. Karshati and dukha is the dharma of this world. 

Therefore those who are highly developed in Kṛṣṇa consciousness try their best to give this knowledge to the people in general, for their conditional life is very much troublesome. 

shackled by iron or gold chains or diamond chains - one must understand it is a shackle; positions are also shackle; false ego of maan is a shackle - OMG relive me from this shackles; ACT for purification; to remove the adulteration; act for pleasure of the Lord; act being part of viswarupa

Condition means an external entity imposing certain things to be met. To be happy there are conditions; to just survive there are conditions - condition means an externally imposed criteria; when its not inbuilt in your nature, you have to meet conditions to accomplish