"'Okay, you're not Robert anymore, you're Robbie', he said.
"I hated it because it made me sound cute — and I didn't want to sound cute. I wanted to be street and cool, and Robbie was just not."
Williams, now 48, admitted despite his reservations, a slight name change from Rob or Robert helped him with fame when he claimed the "order of the day" was "lacerate, dehumanise, vilify, pull down, put a contract out to kill [celebrities], beat them up".
He explained: "It was the best thing he ever did because Robbie Williams isn't me. This person they talked about, that they wanted to beat up, it wasn't me."
His comments come after his former Take That bandmate Gary Barlow coincidentally admitted he "hates" his name, noting he was the first of four people to be given the full moniker in 1971.
In his new memoir A Different Stage, he said: "There were four Gary Barlows born in 1971 and I am relieved to report that I was the first. I hate my name but it's a bit late to be changing it now."
The 51-year-old singer joked that although some names "come back into fashion", he doubts his ever will and quipped that children need to be "protected" against it.