| Quote #1
Yes! they wander on
Coleridge repeats the phrase "wander on in gladness" several times throughout the poem. His friends have a fine appreciation for nature, but the speaker feels a special fondness for Charles Lamb, who has been deprived of nature and happiness because of circumstances in his life. Maybe Coleridge admired the way Lamb dealt with his setbacks because Coleridge had (or was to have) so many setbacks of his own (opium addiction, a failed marriage, the list goes on and on).
| Quote #2
For thou hast pined
Charles's soul is fundamentally "sad" or melancholy because of what he has been through – the death of his mother at his sister's hands, among other things. But Charles suffers through hardship with "patience," knowing that better days lie ahead.
| Quote #3
So my friend,
The speaker knows that Charles is capable of having a deeply spiritual experience like the ones he has had. Is his admiration for Charles a form of self-admiration?