I've also discovered Lupetta's trick after helping look after babies most of my life

....
...my theory is that infants are just getting used to stimulus and have their senses working overtime (...and all the XTC fans just had a bit of a chuckle

....), and even though they are tired, are still in awe of it all...
..both of my nephews in particular would not sleep if anyone so much as looked at them. If they had something to do, they'd do it rather than go to sleep (despute how tired they were). I found if I turned off the tv and pretended to read a book or something, they'd lie down of their own accord and drift off....:)
...My niece was a different story all together, but she was a horror of a baby!

(But I loved her dearly and love her dearly still

)