Dao was toads.
This single sentence encapsulated Dao Ancestor's desire to seek Dao.
Dao Ancestor never cared about anything else when seeking Dao. He couldn't even settle his own basic needs and relied on Brahma Buddha's help. When Qin Mu returned to the first year of the Dragon Han Era and saw the two of them, it was Brahma Buddha who came to beg and acquired spirit pills to keep both of them alive.
Then, Dao Ancestor was fully focused on Dao, and he didn't care about anything else.
Dao was toads. He thought of the ancient gods as Dao and, thus, toads. He used algebra to analyze them. During this million years' worth of time, he refined classic algebra to its greatest potential. He used it to analyze the Great Dao of the ancient gods and morphed it into runes before helping the ten Celestial Venerables construct the Celestial Heavens Realm.
He no longer needed Brahma Buddha to beg for him.