When you were in middle school and high school, you probably created AIM screen names you'd rather forget, had an email address that is too embarrassing to remember, and posted Facebook photos that you've since removed and untagged. All of that is well and good: Nobody uses AIM anymore anyways, you probably created a work-appropriate email eventually, and Facebook offers any multitude of options, from changing your name — as most medical school applicants tend to do — to deleting images.
But Snapchat is not as forgiving. If you created a now-mortifying username when the app first launched six years ago, there is no way to change that username. However, you have a couple of options for erasing the pain.
First, you can go all-in and delete your account, by going online and entering your current username and password. Then, you can create a new account with a new username. The downside of this is that you'll lose all of your existing Memories and contacts. Should you change your mind within 30 days, you can log back in as usual and everything will still be there. After 30 days, your account is permanently deleted.
Your other option is to change the name that shows up with your username. This is what identifies you to friends if you have a less obvious username, such as @moonlightbae (i.e. Ariana Grande). This can be done in a matter of seconds by clicking the gear icon to go to your settings and then going to your name under "My Account." Doing so doesn't alter your contacts, saved photos, or anything else about your account, so it's definitely the less drastic of the two options.
For those who are creating a Snapchat account from scratch, you might want to avoid picking something tied to a current fad or popular Netflix show. A lot can change in a year, let alone six.