It was natural at the beginning. Of course once you realize how awesome it is, you try to do it as much as possible. For me this was mostly learning how to recognize the dream state and how to manipulate it without waking myself up.
I'm not sure how universal this is, but in my lucid dreams exercising too much control from the concious part of my brain would eventually wake me. It was a balance of manipulating the dream and riding the wave of what was playing out. Make a change then wait a few minutes. Don't try to fight it. No side effects of note, except for awesome memories of experiences that are quite difficult to explain.
No idea why I lost it with age. Probably declining sleep quality, less REM sleep. I doubt there's any studies on it but it's a sentiment echoed by many lucid dreamers I've talked to. It's quite unfortunate, a solid lucid dream could lift my mood for days.
>>I'm not sure how universal this is, but in my lucid dreams exercising too much control from the concious part of my brain would eventually wake me.
Man I could get a lot of flying, and fast running, and at times even leveling a sky scraper without waking up. But at times, you wake up for something as trivial as meeting your dream woman.
Basically the problem is with dream recall after you wake up. And establishing a routine so frequent you could witness that routine even in dream, so that you can spot anomaly in the routine in the dream.
Basically there are certain things you can't do properly in a dream. Things like adding numbers, counting, reading a watch correctly twice in a row etc. For some reasons our brains seem to have a hard time maintaining state in dreams. So you establish a stateful routine in wakefulness which would not be possible in dream, making you realize you are now in a dream.
As you can see there are a range of things that need to happen. Routines in wakefullness(like counting, repeating clock check), well rested body, low stress, ability to remember a dream etc.
I think with age a lot of parameters are hard to keep up with.
I have had it very rarely but it is quite amazing how much control one has over how the dream pays out, what you want to see etc. I could literally do a walkthrough in a house, checking out rooms one by one, houses I was familiar with.
I have heard that you cannot see your face reflected in a mirror in a dream. So sure enough when I got my next one I had to try it. I did not see my face, but not sure how much of that was affected by my expectation.
It could indeed just be declining sleep quality. No more 13 hour nights on weekends. Waking up to alarms every day even without work. Constant stress of the grind.
I've considered getting one of those REM signalling masks to recapture my lucid adventures. Haven't taken the plunge yet though
Also, why do you think you lost it with age? Is this like physical abilities that degrade with age?