Speaking up....

One thing I realised in my course of work is that public speaking is not the thing for everyone. I don't really meaning speaking in front of a crowd on a stage in a planned setting, but even those times when you're in a meeting or a small discussion and you've had the urge to speak up but supressed it.
Nowadays, more than not, I've had to sit in meetings with a bunch of older folk... when I mean older I don't mean in months. I'm in my thirties and with any luck, they're not more than 15 years older than me. It gets particularly awkward when you have to do a presentation to 'share' or 'educate' them. These guys must be thinking, "This kid was in his diapers when I started work" or " I eat salt more than he drink water".
Just a few months back, I had to present to a bunch of professionals in their 40s or 50s. Knowing the futility of teaching a race horse how to walk, I decided that speed was the essence. Wrapped up the presentation so fast, they probably only saw the title and thank you slides. Today is another one of those instances. Here I am with a bunch of professionals sharing their thoughts on country policy. Yes I guess I can be considered a policy maker, but sitting with a bunch of people I don't know that well gives me the jitters. I remember having meetings with a whole bunch of directors and managers I knew and speaking up on every instance I had an issue with. Now, in a totally different setting, I am sitting quiet and pretty, with tons of banter and ideas and opinions running through my brain, but without the same confidence and enthusiasm I once had.
It might be age catching up, or unlikely but remotely possible fact that I am getting to be a little bit more matured, but the root cause, I feel, lies with interest. Where what others say or how others react have no more influence than a twig in a forest on decisions on policy, the act of challenging others opinions becomes redundant. And where your opinion is as good as the litter on a food court table, I guess speaking up is no longer a good way to share.
Perhaps there will come a day when I become comfortable enough in my current environment to speak up with confidence again, but I doubt it'd be in this environment.