Same with both of mine!! It was explained to me that the initial settling off to sleep is one milestone, the waking at the end of a sleep cycle, looking around and resettling is another milestone which is a bit more difficult and comes later (although some babies do this from birth - lucky mums!):
I have realised that he's actually pretty good at self-settling initially (he'll be asleep within 15 mins if I just keep putting that dummy back in!) - but he really hates the resettle!!
Initially I would race in as soon as I heard him wake, but after watching him at sleep school, I realised I was actually hindering the process by not allowing him time to try to resettle on his own and learn what he could do without help from me. So then I let him grizzle for a while ie not distressed or properly crying - it's very important to LISTEN to what your baby is telling you, he will let you know if he needs you and then you should respond straight away - it is building this trust in you that will allow him to feel secure enough to go to sleep on his own. Sometimes he would go back to sleep, others he would start to cry so I would go in, give him his dummy, shhhhhh, stroke his forehead then leave the room. Often this was enough (and now if I need to resettle this is all it takes), other times I would have to pat him, shhh, give him a cuddle till he settled and then pop him back in his cot and start the process again. 'They' say to persist with resettling for another sleep cycle, so between 20-40 mins. 40 mins was too stressful for me so I set the benchmark of 30 mins. If he hadn't resettled after that then realistically he wasn't going to and I'd get him up, feed him if it was time and then watch him for tired signs again. When I saw them, I'd put him back to bed.
Just remember not to get too stressed out thinking 'he hasn't resettled and hasn't slept enough today' - this was a mistake that I made and totally stressed myself out! It's a process, it's the repetition and consistency that's important.
It's just like any other skill you teach them - by doing it over and over again! Not much fun for mum sometimes but it does work!
