In an attempt to prove a) that I procrastinate when I should do other work and b) that there is not an exhausting of hops issue I humbly submit this fine artistic rendering.
In the above each green dot is a GoTenna node. Node 0 sends out MSG1 and after much travel, through a mesh network, MSG 1 is delivered to Node 12 (the destination) via 1 of two paths.
Note TTL is the Time to Live as referenced above. Nodes receiving a message with a TTL of 0 will not re-transmit at present.
In this example, there are 14 receiving nodes. However, only two of the original 3 MSG 1 TTL 3 messages were passed on successfully.
Of the messages that arrived at Node 12 one was TTL 0 and one still could have been repeated one more time.
The message was sent out and received by another node 15 times.
Hope this clarifies and shows just how robust a system must be to transmit around tall buildings, factories, houses, trees, pagodas, giant snow globes and a herd of elephants (I heard of).