Question

Why does the poet experience feelings of self-derision,guilt and regret after throwing a log at the snake.

Answer 1

The poet experiences sentiments of self-scorn, blame and lament in the wake of hitting the snake.

This is so because he thinks about the demonstration of tossing the log of wood as unkind, ill-mannered and unimportant.

The snake didn't cause any harm to the poet for which it must be dealt with that way.