Have I ever been left out?

Yes. I have.

I remember that in my 5th year of primary school, I would sit in a corner of the classroom alone during recess while others were out playing soccer. I would look from the classroom window, and while they were playing, I wondered why I never would get invited to play with them. I wasn’t exactly Ronaldo material, but then again some of them were not as well. I remember that on many Physical Education lessons when they played soccer, I would never play.

Why, I wondered. Why was I never part of the huge group of boys that always played soccer in their free time together?

Maybe I’ll never know why, but it occurred to me that there must be some reason for this. I guessed, and came up with a few solutions:
1) I appeared overweight, clumsy and basically not the type who would be active in sports.
2) I was too mischievous, and might "screw up" their game
3) I was just not active/"pro" enough to join their games.
Either way, it just made me feel terrible that I was not a part of their group. On occasion, I would be the odd one out in group projects, and would be forced to join a group I did not like or a group that did not choose me as a member and being in situations like that made me feel awkward.

Luckily, there were a few other friends who were caught in the same predicament as I was, thus I did not feel ostracized and left out as I would be if I had absolutely no friends. This concludes an instance in which I was left out.