Dont have allot of details on this one !

I saw this Movie a long time ago , don't remember much about it.
Young Man escapes from institution, he is perhaps slightly autistic.
Don't know for sure, it could have been an English film . The young actor had dark hair, and was wearing a hooded sweat shirt, perhaps light blue.
His first stop is a diner, were he asks the waitress for a glass of milk and perhaps apple cake. I don't think he can pay for it , the waitress takes care of the tab, she can see the guy has know life experience at all. He than exits the diner , walking down the blvd. That is my memory of the film. It was in color .

Could it be an old adaptation of 'One flew over the Cuckou's nest'? I dont remember there being a diner scene anywhere in the video but movie adaptations based on books can always go buck-wild so anything is possible

I doubt it, One Flew over the Cuckoos Nest came out 1975, This is close to the same time period .

No Idea I don't have much on it Sorry