Relationships are the reason people trust each other, love each other, care about others. Humans are hard-wired in a way that we socialize with other fellow humans and creatures. So even if a person tries to isolate himself or herself completely from other individuals(which is impossible) he/she will not be able to survive.
To love
To get loved
To heal
To get healed
To make memories
To be less lonely
To be vulnerable
To kiss
To hug
To cuddle
To make love
To care for him/her
To do things together
To support him/her
To cry with happiness
To be silly
To be cheesy and illogical
And still, love every bit of it
To miss him/her everyday
To not be afraid to be yourself
To realize someone can be so perfect even with all the imperfections
To realize physical appearance matters but inner beauty matters more
To care for his/her happiness first
To pray for him/her
To belong to someone and be proud of it
To not do something that'd make him/her sad
To give, share, grow and evolve
To share their feelings with someone who is willing to listen
To fight and learn to solve those fights
To smile even when the person is not around you
To grow old with someone and still love them the same
To be someone's lobster❤ (f.r.i.e.n.d.s)
To fit in
To show off
To be sick of it
To experience heartbreaks
To detach from the external world and learn to hate/love yourself
To finally find someone who's willing to love you and handle you for the rest of his/her life
There are many more but I think it's enough for now!
So humans and relationships is an unspoken analogy which will continue to prevail till the human race vanishes