Of course, mundanity strikes as time passes a bit more. Infatuation has subsided and only reappears in sudden flashes, maybe the occasional special day. For the most part, both people have grown used to each other's quirks. Novelty and surprises aren't as frequent, and the partners grow so used to each other that they begin to assume that's how all people act.

Then the downfall begins to swell. Be it civil or in a furious rage, the relationship comes to an end. And suddenly, like a wave, the fog lifts and both people realize that there are so many other versions of people.

That only grows clearer as they date again. New, different surprises come from all different people. A whole variety of personalities and priorities from so many different people can be seen again.

Some Redditors know the whole trajectory, and they were happy to share.

ListerineLass asked, "People who's first relationship was a very long term relationship, what did you think was normal that turned out to be unusual once you started seeing other people?"

First, the moment you'll all been waiting for: sex.

Of course, life in the bedroom for a couple is extremely important--and particular to that partnership. Plenty of people had no idea just how uncommon their sexual experiences were until getting frisky with someone new.

EVERYONE Should Feel Good 

"Probably that I too should be enjoying the sex..that it's not normal to just lay there and have them not pay attention to my pleasure too. I honestly thought sex was all about the guy and what he wants." -- Positive-Platypus

"I've got a laundry list of sh** I realized too late wasn't normal, but the easiest answer is sex. Sex is actually enjoyable when your partner wants you getting off as much as they want to get off." -- SynchronizedCalamity

A Jarring Discovery 

"My first relationship was 18 months (16 - 18years old). My boyfriend was able to keep his erection after he came. I assumed all men could do this."

"After we broke up and I had sex with a new guy for the first time, he came and then obviously went limp."

-- is_it_bedtime_yet

Do Not Take Licking For Granted 

"How much he licked my face." -- AshtonAmIBeingPunked

"Was your ex a dog?" -- Tcheko

"Whole relationship was a punked episode" -- madfuccu

"Are you my ex lol" -- fencing123

"Making Love" vs. "Hooking Up"

"This sounds super dumb, but I was pretty sure sex should look like a movie. The first time I slept with my first partner, it was beautiful - sun coming through the window on a lazy Sunday, candles lit, etc."

"He was super gentle and made sure to always check in through the whole thing. Were together for 2.5 years."

"Imagine my surprise when I had sex in my next relationship and it was on some random person's floor. WHAT A NIGHTMARE."

-- ohterribleheartt

For others, discovering new partners can be a wonderfully liberating experience. They may have been in a long relationship that left them accepting some controlling behaviors on the part of their previous lover.

Don't Bargain Autonomy 

"I found out that it isn't normal to have to explain exactly where you are and what you are doing. Why did I come home 10 minutes later than usual from my job? My current gf doesn't even ask." -- the_beasty_boy21

"Both my wife and I both been cheated on by previous partners."

"We both expected to have to struggle with this sort of thing. Worrying if the other is late, etc."

"We don't."

"I try to be understanding as my work can have a chaotic schedule sometimes. Such as working late, going out of town on short notice."

"But we built trust and these are not concerns we have now." -- Sonendo

Silent, Constant Stress

"Constantly walking on eggshells to avoid upsetting her because she was by nature a miserable person." -- The_Istrix

"Same here. I was with my ex for 12 years. When I started dating other women, I remember mentally flinching in reaction to things that I thought would upset my new girlfriend that would upset my ex."

"Then my girlfriend wouldn't react at all. It was downright discombobulating at first. I didn't realize how emotionally conditioned I was." -- 12random12

When Kindness is Punished 

"Minimal talking/contact with literally any other female because it could give off the wrong vibes, I also had to tell what I did with them in detail."

"She would claim it was 'Caring about you and making sure you're doing the right things' well turns out it was an overload of jealousy and trust issues"

-- T-Poo

And for some, the discoveries went the other way. They'd been a part of a truly beautiful relationship and only realized the full extent of what they had when it was gone.

Startlingly Rare 

"First relationship I was 15 - 18 and he was my first everything. He did not prepare me for how crappy other guys could be."

"I didn't realize respecting me and genuinely caring about my feelings and our relationship wouldn't be a given."

-- eelzetton

The Ultimate Sacrifice 

"First real BF was from 9th grade until I graduated college. He grew armpit hair after we started dating and I thought it was gross and suggested he shave it."

"He did the whole time we dated and long after that, too. It was very weird to get used to men with armpit hair after that."

-- doctorfishie

Simple, But Not Easy 

"I'll let you know when I get out of it, lol."

"In all seriousness, I thought it was normal to look forward to hard conversations, because we always communicated our feelings respectfully and with consideration for our personal bias and the other person's perspective. Go figure, apparently most people struggle with basic communication."

-- xiaomantoubuns