I've got a girl

So, it seems that my friends just can't help falling in love. And by "falling in love," I mean "rushing into relationships with people they may or may not know as well as they should/be totally compatible with." I know, that's a lot to take in, right?
I guess what's eating me is that for the second time since I've broken up with my ex-girlfriend Amy, I have watched, painfully yet again, a second great friend of mine rush/jump/dive right straight into a relationship with an incredibly great guy, but it just may not be an incredibly great time. I'm tired of it, and I don't know how to stop this trend. They say ring by spring, and it's now October, soon to be November...
The first time I had to endure this was with one of my closest friends last semester. She didn't have anyone, and hadn't had anyone in quite a while, so when the first great guy came along to flatter her with a date, she accepted and never looked back. Even when it looked liked things weren't going to work out, she didn't try to move on, she waited and pushed until things would work out and forced the relationship. Now she has become a source of, yes, incredibly great friendship, but also, on occasion, a source of incredibly great sadness and envy. I'm envious because I wish to have my best friend back, and I know that the time I do get with her is not the same time we used to spend before. Don't get me wrong, her boyfriend is a great guy, and I love him and respect him and wish him the best in all of his dreams and pursuits. But being in this relationship has changer her. Changed her to a person I almost don't even know anymore.
Now, I have to endure this a second time. Another incredibly great friend of mine has rushed into a relationship, again with a really good guy, but just a really bad time. Since she broke up with her boyfriend of TWO YEARS about TWO MONTHS ago, she has had three gentlemen callers, counting the new beau as numero tres. I like him. I like him more than the previous two. I liked him before she liked him and he liked her. But he too has been the gentlemen caller for three ladies this semester alone (counting my friend as the third), and he's only been here two months. Both of them agreed to take it slow and for him to pursue her slowly. But somehow, they decided they were mature to hit it early and now the rest of us get to watch them stumble through the morning after the honeymoon, and hope they make it out alive before somebody goes away hurt.

I say all this not to say I wish people didn't date, but to say I wish people used better restraint and judgement before they jumped into something as serious as a relationship.