The first time I was in REAL love was with someone I ended up being with for almost 5 years...
I mean, it may feel different for guys then girls but how I felt was I felt like he gave me feelings no one else ever has.
And when I held him and kissed him it made me melt.
He completely satisfied me in bed, made me laugh when I was upset, talked to me about my problems and helped me in anyway he could.
A lot of things he did let me know he really loved me and cared about me.
And I felt the same way about him and did the same for him and loved doing it for years to come.
You'll know you're in love when you think for years ahead how your future will be with them and try anything to be with them and stay with them...
At least; that's mostly how I felt.