I can be extremely intense. I never used to know what it was - I just thought I was a very passionate person. I remember a number of years ago I met this lady from Iran - a friend of a friend of mine. We had a very strong connection at the time - it was like there was no-one else anywhere near us - and we were in a room full of people. It was insane.
I've heard that most people diagnosed with bipolar question it - and I do too, quite a bit. But when I think about even a few of the things I've done I realise I've acted completely irrationally a lot of the time. My wife reminds me of those times too, so that helps.
Maybe you should talk about this with a psychiatrist? And keep an eye on those symptoms? They will be very wary of diagnosing bipolar - but it's worth talking about with someone.