Why did Jesus teach love as a commandment? Because to focus just on loving God and the neighbor was so liberating for the Jews who at that time were up to their necks in commandments.
Secondly, Jesus was not an autobiographical preacher. You have to read between the lines for clues to his personal life. He taught the command to love God with all our heart, soul, mind, and strength was the greatest commandment because he lived that quality of love, knew how totally awesome is was to have that kind of relationship with the Father, and wanted us to share it.
Third, a divine commandment expresses faith in what we can do and be, orients our life, alerts us to the fact that the rewards of following are better than the consequences of rejecting, and promises support every step of the way.
You can see it in the image above. The giving of divine commandments is an act of love and Fatherly kindness, received in utmost worshipful gratitude and respect. Woodcut of Sebald Beham of Moses receiving the ten commandments, from the prayer book of Martin Luther, 1527. https://upload.wikimedia.org/wikipedia/commons/thumb/5/50/Ten-Commandments-Luther-Beham-1527.jpg/128px-Ten-Commandments-Luther-Beham-1527.jpg
Watch the 11:22 video or listen to the podcast episode.