No teeth yet, and every visitor wants to check his gums

Every relative who comes over puts a finger in his mouth to check. Half the babies his age at the park have two or four teeth already. He has none, eats everything mashed, drools like a tap and seems perfectly happy about it. Our doctor isn't bothered at all. My athamma shared her own theory at lunch today and I nearly lost it. When did your late teethers get their first one? Mostly I'd like to hear it's normal from someone who isn't a doctor or an athamma.