its hard to say WHAT is normal for anyone which is a REALLY wishy washy answer!
sorry
Ethan went through a phase when we were visiting relatives in Canada (from the UK) where everyone was playing with him and admiring him and like your wee man, he just assumed that the world existed to ensure he was entertained!
As he got more able to do things, he relied on us less for entertainment. (not to say we don't have our days where he just wants us to entertain!
) we spent a lot of time showing ethan his toys and what he could do with them. certain faves emerged (often the toys we least expected, like a wooden spoon at one point because he could bang on the floor!) and he could play with them for longer... he liked to make noise so we found noisy toys (even if it was a tub full of rice that he could shake), then he liked to put things in his mouth so we tried teething rings and eventuallly relented and provided raisins (apparently swallowing them was part of the fun!) At nursery they discovered that ethan likes to move things and so they would secure him into an old silvercross pram that he could bounce. Once he figured out what toys could do, he could play for longer.
hth!