My little guy, now almost 16 weeks, has been doing a lot of one hour naps lately. AFter a 45 minute nap, he'll often take the paci and go back to sleep, but not usually after the one hour. Just like yours, mine will wake up all smiles but will want to go back to sleep too soon.
You are not alone!
Have you tried the pacifier to get yours to go back to sleep? It's not the perfect way to go, but I've found it works for mine more often than not.