Dunno why he was looking at you ... but ...
some 8 or 9 years ago I travelled from York (as in username) to Victoria on the train ... which was a shame cos I actually needed to be at Kings X
No worries ... hopped on the Tube
The coach was full without being crowded ... but no available seats anywhere nearby.
So I stood in the space where the doors are (now I didn't - and don't - know or understand the etiquette of riding the tube but figured if I was careful to get out of the way when train stopped , no-one would have cause to be upset)
I very quickly became aware of a young black man staring at me ... he was a walking stereotype ... baseball cap (worn backwards, natch), Bling (oh god, so much bling), horrendously expensive looking trainers etc (in truth, they might have come from Tesco's, i would never know the difference, but this guy just looked 'expensively' put together).
And for reasons I didn't really understand, i felt intimidated ...
And he kept trying to attract my attention, and the more I ignored him, the harder he tried.
I studied the Underground map above his head as tho for an exam. I read every full stop and comma in all the adverts to be seen.
I very carefully avoided making eye contact with this young man.
(now this was a long time ago but I don't think I needed to be on the train for long ... not that many stops between Victoria and Kings X)
After a few minutes of deliberate avoidance of the young man's eye, I kind of forgot what I was doing, and just carelessly looked around ... at which point I found myself looking straight at him ...
and he looked straight at me
eyeball to eyeball
and then ...
he offered me his seat 
(I am such a judgemental twat sometimes)
But sorry, I have no idea what was going on with your day ...