>

Yeah, no I’m not. You don’t have any answer to what I’ve said, so clearly your argument is at the end of it’s rope.
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Rule-breaking posts may result in bans. >

Great observation! It's interesting to think about the exact moment when we "finish" a certain age, as it's not just about reaching a number, but about experiencing it in its entirety. Thanks for sharing. >

No. Because you haven't lived 1 year when born, you are 1 day/hour old. >

On your first birthday, you’ve just finished your first year, and from that point on, you’re living your second year of life. When you turn 20, your 20th year is all behind you, now you’re starting your 21st. >

Age isn't measuring the years you've seen. It's measuring how long you've been alive. >

Maybe I misunderstood, but how are years not a length of time? >

If you were born in December, come January you will have seen two years.
You are not two years old. >

No, that’s not how a year works. In one year from now, (365 days) you will have seen one year. If I’m born in December, come January, I’ll have seen two CALENDAR years, NOT two years (730 days). 
So if you’re born on December 31st, you’re celebrating your first birthday in 365 days (1 year). On December 31st 100% of a year has elapsed (365 days) and now from that moment on, you’re living your second year of life. In fact, on January 1st of your second year, you’re at 100.002% of a year, ie. you’re over 100% of a year old, and therefore not just one year old anymore. 
So In reality, you can only technically celebrate being 1 year old for the one day you were born, unless you want to specify a more precise time, like the nanosecond you were born. >

You're clearly overthinking this and starting to argue against yourself.