i mean yeah he was essentially older than his class - he started at age nine and previously the oldest youngling accepted was five at the latest
he was NINETEEN while still a Padawan in Attack of the Clones - Ahsoka by contrast upgrades Youngling>Padawan by 14 in season 1 of clone wars and gets offered Jedi Knight rank by the Council at only SIXTEEN, four years earlier than Anakin was offered the promotion at age 20 shortly after AOTC.
Admittedly these aren't that strange, the Padawan>Knight pathway usually happens much later, Obi-Wan was still a Padawan at age 25 in Phantom Menace after all - Clone Wars accelerated th training and promotions.
Anakin is also unusual though because he started Padawan training at the youngest - normally you go from Youngling>Padawan in your teens (Yoda picked Dooku as his Padawan at age 16 for example) but Anakin basically skipped the sequence and became a youngling and padawan simultaneously.
Taking on a Padawan is how you become a Jedi Knight and Obi-Won was rushed into Jedi Knighthood after the death of Jinn at Maul's hands. This basically gave him early access to advanced training he did simultaneously (like night school) in addition to normal youngling activities. It was cram school, which is why he didn't end up lagging behind and surpassed his peers by the time we see him a decade later in episode 2.