Not me, but my oldest boy on his first bike at about age 4 -
We still have it. He fired it up a while ago, just to smoke up the garage...
Here he is 17 years later -
He also has a '98 VFR 800 that recently replaced the 2 Ninja 250s he rode for about 4 years after getting his license.
He's got
"the gene" (the motorcycle/speed one).