[it seems you have momentarily lost the hobbit with this talk of space/time tangling with memories, but he tries to understand it]

The journey to and fro makes it difficult for a person to keep track of it?

[it seems like in all the great tales, it was great warriors that were at the center of all great things, but Frodo thinks then of Bilbo. He sounds wistful for a moment]

Or sometimes one clever or bold enough, despite how they may look or feel setting out, or how great or small they are, may be the very person that changes the tides.

[he doesn't think he is that sort though]

Their war must be terrible if it has come down to such desperate measures.