I have bursts of happiness (no, not like that) but taking a macro view of myself as a whole I'm not sure I've ever been happy for an extended period (say for more than a few weeks at a time). Like a lot of people, throughout my life I've had some setbacks and they tend to keep me grounded.
One thing I have learnt as I've got older is that self-centred social activities make me happier than expected, e.g. I've never been one for celebrating birthdays but I really enjoyed my 30th birthday party and it made me wish I'd celebrated birthdays in my 20s. It may sound cheesy but my wedding day was also probably the best day of my life, as it was incredible having all those people there and being the centre of attention, it was like a massive high for 10 hours. Neither my wife nor I are what you would call 'popular' in terms of being in the cool gang at school, life and soul of the party etc, so such experiences are quite rare.
Another surprising source of happiness is watching my son smile; I was expecting to draw happiness from watching him develop etc, but I wasn't prepared for the rush I'd get from something as simple as him grinning at me. In fact it has actually changed my outlook on the importance of facial expression (I'm known as someone who rarely smiles), I never realised how powerful it could be so I am going to try and smile a lot more at others.