39... for the first time

Tomorrow is my birthday. So far it feels like it will be like any other day. I used to love my birthday & made sure all the people around me knew what day was coming up. I don't feel like doing that anymore, is that a sign of getting old? Sometimes I have to ask my kids how old I am or I have to add it up real quick when asked. Not this year.
39.
Next year I'll be 40. Soon I'll have to start checking the "40-50" box on surveys. What a weird feeling. I used to think 30 was old. I couldn't imagine being 40. When I talk about someone and I refer to them as 'older than 40' then I'm really saying that they are LOTS older than me.
But they're not. YIKES! I'm having a reality moment. Mortality.
But you know what they say... "You're only as old as you feel."
I better get to bed.
I want to feel GREAT tomorrow. :)