4yo collects odd things & has shaking screaming fit if he loses them

[voyagerfan]

My 4.5 yo ds started school in sept and seems to be getting on fine.
HE's recently started taking really odd things to bed like a pot of lip balm, a pen, a large plastic toy, hardback books.
In the night he wakes up and if he can't find the thing gets out of bed, turns on the light and cries really hard and is shaking and sobbing until I find the thing.

This occasionally happens in the day as well, eg when he'd taken a car to school and we started going home he thought he'd left his car at school, same shaking screaming fit.

Is this just a weird phase?

Both of mine went through this - DD had to do things in a certain order and if I interupted her, she had to go back to where she began and start again! She also went through a stick stage, pebble stage and gravel stage - all being pocketed in her school coat.
DS went through the stick collecting stage too so I think it's normal. They want their own little workd and belongings and if anyone dares to interfere, all hell breaks loose!
If on the other hand, it got much worse and became like OCD type phase, then I'd get a medical opinion.

'own little world' that should have said.

My DD2 does this. She specially loves tiny of sparkle/plastic or buttons. If she loses one, all hell breaks loose.

Am hoping she will grow out of it.