I remember saying to DH, when DS1 was at pre-school, how it is amusing that we all think our child is better, nice, handsomer, cleverer than everyone else's.
I mentioned, as an example, shamefaced, that "I often find myself thinking that DS1 must be their [the pre-school staff's] favourite, but I know that's stupid and I only think that because I'm his Mum."
DH looked horrified. He said "Well of COURSE he's their favourite. You can tell he is."
I said "Er no, DH, you just think that because you're his Dad."
He said "But he MUST be. He's so sweet!"
And DH is the most sensible, rational man you could ever meet. 
TBH if pre-school staff, restauranteurs, teachers etc make parents think that they love their children, then they are doing a bloody good job.