What are the common relationship issues?

I feel like my relationship is one-sided

My partner and I don't talk any more - it feels as if we've drifted apart...

Me and my partner have really different attitudes towards parenting

I've found out my partner is having an affair, what should I do?

I've had an affair, how do I tell my partner?

Me and my partner have very different values..

My partner is always criticizing me...

Everything my partner does irritates me

I can't seem to stop arguing with my partner. What can we do?

ETC......

Statistically an average relationship lasts 2-3 years.

I feel like there are just few main and common reasons for all these type of issues in relationships: not the right match, you can't be yourself with your partner, you are not completely honest with each other.

In the past, I struggled a lot in the relationships which started great and seemed like I was with the right person, but a few months later it inevitably would start moving to the wrong direction.
It's both of our faults, we didn't completely match and we were not completely honest about our desires and preferences with the partner.

There are ways to learn and understand how relationship works on a deep level so you always will know how to attract the right person, avoid dumb mistakes, and how to start the relationship you always wanted.

Not accepting that men and women are simply built completely different.

Women like to talk, show emotion, talk about emotions, analyse, think thoroughly and share...

Men are not like that, so women often expect too much from their partners.

And vice versa...