We do send out birthday card in China, especially in the office. Everyone, except the birthday star, will sign and write their wishes for him or her on the card. And the funniest thing was that one of my coworkers bought a birthday card for herself.
Life is amazing. The I at my 20s might not understand as much things as the I at my 30s. I feel comfortable with getting older and older. That is just how things go. Grow and change. Like a rainbow, there are different colors at different times, which makes our life colorful.