Why Follow a Madhab if we Have the Sunnah?

“How does one pick a madhab?”, I wondered. Is it by random or do you have to study each one then select the most appealing one? I had just bought all 9 volumes of the rarely found Sahih al-Bukhari in New York at the time. It was like having a treasure. My evenings were spent engrossed in its chapters, mesmerized by the amount of details recorded about our Prophet.