Why does it seem so many relationships end after 3-5 years

You reach your level of tolerance for that human being and want to escape.

>>17686263
This

>>17686260

Is this a rhetorical question? Spend even a moment to consider the many reasons why this is the case and it becomes self evident.

People convince themselves they can change the other person, and eventually realize they can't.

People act/present themselves as being better than they are, but once they get comfortable "let themselves go" either physically or behaviorally.

Two basic and overarching reasons that can encompass a lot of the reasons why relationships of that timeframe end. There a dozens more if you bother to think of them.

And really, I'd call a relationship ending at that time a success. Good fucking thing they ended that now, instead of trying to wade through non successful relationship ending in misery and divorce.

>>17686260
Because you are depressed with where you are in life

>>17686260
Because one of you will get too comfortable in the relationship and not care as much.

That is the time when you have to decide wether you want to settle down together or not, and many people realise they don't want to spend the rest of their life with this person

>>17686260
You're something like 18 or 20, right? Are you the same person you were at 13 or 14? I certainly hope not. So are you likely to be wanting the same things from a relationship you wanted back then?

As you get older and more settled into a personality and identity, relationships will last longer because both of you will remain who you are longer.