Why: Arjuna sees hosts of gods entering into Krishna, some praising him with joined hands, while great sages and perfected beings praise him with abundant hymns, describing even divine and highly realized beings responding with the same awe he himself feels.

In life: it's reassuring, in a moment of feeling overwhelmed by something significant, to know that even people you consider wiser or further along than you would likely feel a similar awe in the same situation.

Teaching: don't assume your own overwhelmed reaction to something genuinely significant means you're less capable or less advanced than others, this verse suggests even far more realized beings respond with the same wonder.