Ted Mozby once took Robin on a date. And despite all his introversion, he stole a blue horn just to impress her. But then his best friend Barney, a womaniser, swooped in and used one from the playbook to win over her. It worked, and they had a good run when Ted was heartbroken, but remained happy for his friend esp. because he followed the bro code. Ted did not have a confidence issue, he was able to meet someone else and had a decent life and loved her till her demise. What bothered him more wasn't that Robin choose Barney over him but that she gave someone like Barney a better opportunity to get to know her than him. If only she had done the same for him, he would have shown her how much he loved her, enough to break character and steal a blue horn for her.