Shall I say, I have gone at dusk through narrow streets
And watched the smoke that rises from the pipes
Of lonely men in shirt-sleeves, leaning out of windows? . . .
Prufrock does not know how to introduce himself as a topic of discussion. He doesn't know how to address himself in the right manner. It's as if he intends to use his visualization of lonely men as motivation. Due to the fact that he doesn't want to share the same fate as those men.