Yep, agree with everyone here that you're not being a jerk at all! Humility is overrated, never really understood the stigma behind saying good things about yourself as long as you're not saying bad stuff about others :'D
I'm not great at being encouraging so I usually don't comment on achievement posts, preferring to just like and move on. Sometimes I'm worried people would pick up on that pattern and conclude that I'm actually salty, but that's probably being paranoid and people have better things to do than tracking my posting habits
But I just wanted to say for the record that I'll never, ever think someone's a jerk for celebrating their accomplishments, no matter if it's something 'dumb' or 'petty' like 34 views or something incredibly enviable that most of us are very unlikely to achieve :]