It's handy to have a label to attach to people. Liberal, conservative, libertarian, etc. are all convenient ways to pigeonhole individuals and their beliefs. But, are such labels valid over time or across diverse subjects? I don't think so.
A saying I heard which seems to be generally valid is, "There's something unnatural about a young conservative or an old liberal." This makes sense if you accept the concept that conservatives generally want to keep things the same and liberals want to change things.
A basic pattern with the young seems to be to want to change what exists, to do things differently. They don't want to have to live by their father's rules. This, by definition, causes young people to be labeled "liberal." Whether they're just rebelling against the establishment or they don't have enough life experience to properly judge an issue is irrelevant. They just don't like things the way they are and have different ideas of how things should be.
Usually, this is more open, more inclusive, and more liberal. They feel this way because the existing rules, the establishment's rules, weren't designed with them in mind.
Those who are active go about causing change to happen. Sometimes they succeed and sometimes they don't. But even when they don't, they move the issue in their direction. And this is where they start changing into conservatives. (Remember, we're not talking about radical liberals or radical conservatives.)
Imagine now its a few years later. The children or grandchildren of these liberals are coming of age and beginning to question the wisdom of how things are. They start challenging the accepted ways. And whose ways are those? Their father's and grandfather's. So what starts to happen?
The older generation (the old liberals) starts to defend the changes they brought about in their youth to make the world a better place to live. If those changes are being challenged now, that implies that they weren't the right or perfect things to do. But, how could this be, asks the older generation? We worked so hard to make things better. And we did make things better. Now these youngsters want to change what we accomplished.
After a bit of back and forth, the young (the new liberals) begin to see the old (the old time liberals) as conservatives who are trying to stop change, to stop progress, to maintain the old ways. Without realizing what's happened, the old liberals have changed into conservatives.
There is another reason for young liberals to turn into conservatives. During their lives, they have acquired things. Position, economic security, legislation to meet their needs, life experiences, and have generally adjusted their lives to fit established norms. They have become the establishment. A basic criterion to be a conservative is to have something to conserve. They have acquired those items listed above and want to keep things comfortable and "normal". The young haven't acquired much and little reason to perpetuate the status quo.
I was considered a Young Turk in 1970 when I first got involved in controlling growth in Petaluma. By the time I left office in 1990, I was considered a part of the old guard who resisted change. When I began my employment career, I couldn't understand the resistance to change in the organization. By the time I retired, I was appalled that these new, young people wanted to change things without realizing the reason and need for existing procedures.
I hope you older readers can relate to this discussion and you younger readers will realize that, at one time, your fathers and grandfathers felt the way you do today.