Dating is the meaning of life?

Okay now let me tell you something disturbing. Two times this week somebody has assumed that I'm dating. The first one was a customer who asked me how I was doing and brightly I said "I'm good" and he responded "oh so you've found someone, why else would you feel so good!"
The second one was my old teacher whom I bombed in to at the mall. I was spending time with a friend of mine, who happened to be in his green army clothes at the moment, so my teacher said "oh and you got a handsome man by your side, so it's all going well for you!"
Firstly I thought about this customer, who is regular in our store, was it obvious that I had been (note still am) single? And why why why would a boyfriend be the only reason for me to be happy? Same thing with my teacher, I told her I had two jobs and an apartment, wasn't that enough for her to say it's going well for me? Why do I also need a boyfriend?
I'm getting sick of this fuzz about 'getting a guy'. Why can't I be satisfied with my life and being single? I'm still under twenty, what's the rush here?