I was lucky to get a job in the USA that didn't care about my age at all as they were very much welcoming of all walks of life and all ages as long as you had the chops for the job. I learnt so much there than I have since coming back to Australia.
Then, I had just turned 23. The volunteers and staff didn't care about your age at all (apart from making sure you were over the age of 21 before they offered you a beer) and it made the job easier. Frankly I don't know if I would have lasted as long as I did if it wasn't for that being a non-issue. I am sure that this isn't the case for everyone working with volunteers in America, but for me it always felt like people wanted to be there and would take on any advice or opinions you had even if they had been there 10 years longer than you. You were the staff member tasked with running the program, they were the volunteer.
Back here in Australia however, this isn't the case. First, I want to precursor this with I have been volunteering for various organisations since I was 15 years old and I continue to do so (and likely will for the rest of my life). I absolutely understand when someone steps into a role above you with less experience within the organisation/cause you are passionate about, that you will look at them with suspicious eyes and a raised eyebrow. I expect no less from volunteers who have been deeply involved and have done amazing things for a cause; clearly they have been the ones who have made it what it is today.
But, there is being hesitant and then there is being outright dismissive. The moment I stepped into roles back into Australia, I was met with "What would you know? You're too young." At this point I am 26 (I seem to interview for jobs before my birthday and start them after my birthday I've just realised. I was 25 when interviewed but didn't start until I was 26).
Now interestingly enough, I was too old now for a lot of roles I wanted to get. There are environmental jobs here that have a cut off of 24-25 years old. So I have spent 2 years in New York working my ass off to get experience and to increase my chances of full time work in Australia when we moved back. But instead it seems I have missed my prime time to get hired. So after about 20 job applications for the last 5 months of work in NY I land a job. It's only 3 days per week but the organisation and it's cause are something that I wanted to get behind wholeheartedly and was excited for.
I was frustrated. My boss at the time was only 2 years older than me (my current age now, 27 going on 28) but he was taken more seriously that I was. In all likelyhood a portion of this was likely a gender issue but I was also seeing bias being passed onto volunteers I had brought on that were University students. They were new, what would they know? Millennials, they aren't productive or socially conscious for society and are just using us for a stepping stone. They don't care. And that was the bulk of my problem.
Now, I have gone through 3 bosses in the last 2.5 years of being with this organisation. When this happens, myself and the other staff member take on the workload as well as our volunteer President who isn't much older than I. I ran the organisation for months while we searched to replace my boss and yet, I still wasn't taken seriously due to my age/experience.
I have been open with my job that I am always looking for more work, but I can barely get in the door. Why? Because I don't have enough experience. I am now 27 going up against people who are 10 years older than me who have 10 years more experience than me because there has be a sharp decline in environmental work. There isn't as much funding out there anymore and mass job cuts from our major environmental governing body about 4 years ago (DELWP - this name has changed about 4 times), caused a lot of people to hunt for the 3 days per week low paying jobs that are entry level. They are old enough for the job but I am not.
I'm likely never going to be able to contribute my passion, my experience, my ideas in any major way because I am too old and too young for the workforce. This isn't just my case, many others around my same age in the environmental industry are facing the same issue.
I thought it would be better when I was older, but it seems to just be getting worse. This won't stop me from applying for more jobs and being hopeful though.
Here is a great video which really summarises what Millennials come up against.