M.N.
Hi! My first daughter was colicky! Very cranky. There were lots of tears, both hers and mine!
My son is a ball of happiness.
My daughter/first was never very outgoing or easy to smile. I really had to work to get her to smile or laugh. To some degree she is still like that at 5. She is just hesitant and shy.
My son/second has been very outgoing and happy. He smiles and laughs so easily. (it is ironic to write this now, as he is teething and cranky)
My kids are totally oposites, night and day. You can never know what #2 will be like until they are here.
Good luck