I know! What am I thinking??? This is insane! Young people are stupid and crazy and need to go be wild before they can possibly commit to anything, right? Besides, you don't even know yourself yet then, so how can you know/love/commit to/be with someone else? IMPOSSIBLE!
Meeting someone later in life, on the other hand, is a recipe for happiness. You already know who you are and what you want and aren't going to make the silly mistakes those 22 year old halflings made. You will know how to commit while holding on to your identity and maintain the perfect balance of your priorities and your partners.
So.... just for fun, let's pretend that there are some downsides to meeting someone later in life. What would those be?
Change is still a thing
Sure, we change a lot in our early adulthood: moving out, studying fifty things before settling on a field, finding work in a totally different field, travelling, and basically experiencing life on your own terms for the first time is sort of a formative experience. I am not convinced, however, that I am done with the formative experiences just because I don't have a "2" at the beginning of my age anymore.
Take the most traditional post-marriage experience: parenthood. Oh my goodness, if anything is going to challenge and reshape the very fabric of your being, I'm pretty sure that's it. (Not that you have to have babies or anything, but still: if you did, it would be pretty life changing.) So by the "wait until you know yourself" logic, should we try out having babies before we commit to a partner?
Start when you're still youthful and you just go through more of the life-changing experiences with someone else.
Youthful stupidity or baggage-fuelled stupidity: you pick
Sure, I have experience to tell me what I do and don't want out of life and a partner. I also now have an established history of falling totally in love with people who are only kind of into me, which may or may not manifest in a tendency to spend a relationship looking for evidence that the other person doesn't really love me. Super healthy, right?
Those young, blushing couples have way less opportunity to build up baggage and insecurities and weird relationship fears to subconsciously use against themselves and their partner.
Life gets rigid
I have routines and organizational systems and a busy schedule. I have my home set up precisely the way I like it to fit said routines and systems and schedules. What? Now I'm supposed to change the awesome life I spent so many years fine-tuning just to make room for someone else's bed time, morning cuddles, and weird eating habits?
On the flip side, if you just so happen to meet your shining lover at a younger age, you get the benefit of building your routine and life together from the start, removing this horrible transition where you get all annoyed every time you see their stupid messy desk in your previously-perfect living room, because it's always been there. (Okay, the desk might still annoy you.)
The clock, oh the clock
Speaking of parenthood - that stupid biological clock is a THING and if you want to have babies of your own and you are a woman (or a man who wants a partner his own age, thanks), you are on a bit of a time limit. No, not a ridiculously oppressive time limit, but it does mean that you will have less time to enjoy just being with your partner before you start having to make critical decisions.
Oh, and when we're in our fifties with teenaged kids, I'm pretty sure our friends who had babies when they were younger will be living the high life. They will be royalty and we will be the sleep-deprived serfs trying to balance kids, careers, our relationships, and don't forget about elder care! Our parents aren't getting any younger, either.
At the end of the day this is all moot, because we all have zero control over when we meet a person who will be a good match for lifelong partnership (if we ever do or even want to). I guess I'm mainly asking if we can please stop judging young people who decide to commit to each other just because they're young? I know it's hip to be older and cynical and everything, but that's not the way things have to be.