[01HNNWZ0MV43FF]

Maybe they meant 5.5 years old

I see a lot of European languages will say "I have X years" where English says "I am X years old". French at least

[usrusr]

Specifying the unit for human age feels a bit formal in German. The unitless number is colloquially used like an adjective: "I am X".

[bagels]

Thanks, that makes a lot of sense in context.