Forty is not a crisis, even when your body starts adding sound effects. Everything is still fine. You may just hear a few extra creaks when you stand up, sit down, or walk across the room.
It’s a good 40th birthday meme for anyone who has started noticing a few new aches and sounds. They will recognize the feeling right away and probably laugh before getting up very carefully.
There is no need to worry about every pop and crack. Turning 40 is still worth celebrating, and a little extra noise does not have to get in the way of a good day.