I still get asked for ID occasionally. Im 27. I dont even have that much of a baby face, especially when its covered in stubble. Unfortunately, this happens, and while it's annoying to be asked, they do have a duty when selling alcohol or tobacco products to ensure that they customer is of the legal age, the fines the seller can face, and the individual that serves underage people can be monstrous. Also, Im not sure about elsewhere in the world, but I do know that underage people are paid by the governing body specifically to catch people out.
I suppose it is a compliment, for me at least, to be asked, Id rather look 9-10 years younger that 9-10 years older ^^.