Thx Carmel, oh, if cats can have dream, he probably had a bad dream, that explains his weird behaviour. He wasn't on any medication or flea treatment, nothing unusual happened, he just woked up and seemed lost, I happened to be near him and watched him throughout. He took some mins to get up from where he sleeps, took quite some mins to walk cautiously back to his room, testing or investigating everything with his paw. Back in his room, I thought he would be more relaxed, but alas, those toys and furniture in his room seemed alien to him. Checking everything out very cautiously with his paw 1st, then sniffing. 1st time I witnessed something like that happen. I don't remember how long he slept, but he usually take quite a couple of hrs' nap daily in the late morning before asking for food.
Ya, he seem fine now, nothing unusual after that episode.