I certainly do remember the middle platfrom at Forest Hill and remember when the 'fast to Forest Hill' trains from London Bridge stopped there.

Here's a true story: In about 1978 after an after work pub visit in central London I rushed to London Bridge station and found that the last train had just gone. It must have been close to midnight. A passing train driver heard me moan, asked me where I was going and said I'll get you to Forest Hill, just get in the cab of that diesel loco over there. It was a diesel locomotive with no train - just the loco. He walked over to a phone on the platform, had a chat with someone and then climbed up into the cab next to me. He explained that his original routing was going to take him through Forest Hill but only on the middle platform and that he'd called the signal box to route him via the regular side platform. We then trundled off down south with no stops until Forest Hill where he dropped me off. Of course the ticket office was shut and the station locked up so I had to climb over the wall and walk up home.

Can you imagine anything like that happenning in 'elf & safety' Britain now ?