Relationships can be complicated in a myriad of ways already.

You have someone besides yourself to think about every day. Not only do you have to deal with issues that may come up between the two of you, such as family and finances, but you also have both of your friend groups to factor in as well. In your friend groups, you may have friends who happen to be still single. Friendship dynamics will likely change when you enter a new relationship. It is an adjustment period for anyone directly associated with you.

If you happen to be single right now and you are not happy about it, do NOT, I repeat, do NOT make people who are in a relationship feel bad for not being single.

That's just a shitty thing to do. If your parent died, would you try to make your friends feel bad just because of both of their parents still being alive? I didn't think so, because that would be a horrible thing to do to anyone.

Unless your friend's significant other is doing something horrible such as cheating on them, there is no need for unsolicited input of advice from you. Let them be happy together. They do not need any of your petty bullshit. Relationships tend to happen when one least expects it.

Instead, take this time to improve yourself for when you do start a new relationship. Try to keep an open mind and not think that a potential relationship is going to end before it even begins. Do not complain about being single all the damn time, because nobody wants to deal with that. Do not talk about your ex or put them on a pedestal. Throw away all of your saltiness already.