My daugter was the same she knew what to do at 1 year old but she wasn't interested until she was 2 and about 4 months she's now coming off night nappies but i'v leart to take it at her speed not mine. will do it in his own time.
you say rewards, I don't know if you have tried an actual reward chart he can work towards a goal maybe trying to fill the boxes with stickers and you can make the boxes to suit like 3 to start off with so he only has to use the potty or pan 3 times a day then once he can do this you can put 5 boxes until he gets a reward.
hope that helps, good luck xx
Anyone potty training? Got any tips? My son knows what he has to do, he just seems too lazy to be bothered. I have tried reward, but this only lasts a few occasions.