So we learn from his Wiki:.
In his youth, Venter did not take his education seriously, preferring to spend his time on the water in boats or surfing. According to his biography, A Life Decoded, he was said to be never a terribly engaged student, having Cs and Ds on his eighth grade report cards.I can't say I guessed or suspected as much, but I must say it doesn't surprise me: while there is surely some correlation between academic achievement and achievement in later life, still the world is littered with the resumes of successful people who took their time getting their life in gear.
I learned about this phenomenon some years ago in the work of the late Liam Hudson who (inter alia) studied the careers of prominent scientists and found that a lot of them were not the swots in school. Per Hudson, it was rare to find a big name who rose from the lower depths, but that in a more-than-random number of cases, they weren't the A students either. Often, what they seemed to have (if I remember right), was a taste for engaging with what interested them; a patient curiosity, and perhaps also (especially valuable in academic science) a knack for formulating doable problems: workable devices for exploring interesting questions.
Per Hudson, one field where there did seem to be some correlation between academic success and success in later life was the law. The inevitable suggestion was that this may be a field where it really doesn't matter what kind of skill you have as long as your resume looks right. We may prayerfully hope that this is an insight that applies to the old (and now defunct) closed shop of the British Bar, with no relevance to the more Wild-West ethos of their American brethren.
There's an interesting obituary of Hudson here although it mentions nothing about his work on predicting creativity. I do love the line about his professorship at Edinburgh where, it says here, "he was probably more esteemed for his writing, his illuminating conversation and his energetic promotion of the educational sciences than for his dedication to professorial chores." A guy who worked on what engaged him, I surmise.
There's a more extensive review of his work here,