I celebrate it by getting better. Once it's past the summer solstice, that means the days are getting shorter! I always feel better after the summer solstice, I have more energy, am more cheerful, etc.
_________________
"Of all God's creatures, there is only one that cannot be made slave of the leash. That one is the cat. If man could be crossed with the cat it would improve the man, but it would deteriorate the cat." - Mark Twain