Dabbling

Today I want to discuss the related issues of passion and dabbling. Not erotic passion -- I think others on the web have addressed topic that ad nauseum. No, what I'm talking about is passionate pursuit of excellence in a field of endeavor: An art form, scientific research, intellectual discourse, business, or any other area of human activity.
I am a dabbler. I suppose that I say that somewhat apologetically, somewhat defensively, but, I think, accurately.
Over the course of my 48 years, I have been somewhat successful at many things: Journalism, science, architecture, marketing, painting, piano-playing, even Ukrainian egg decorating. But as I look back I can't say that I have ever achieved real, lasting, consistent excellence in any of these areas. There have been occasional, sometimes even frequent, moments where I've exhibited skill, talent, maybe even a flash or two of genius.
What I have lacked is any sort of abiding passion that has driven me to excel in these areas.
I'm a great student. I love to learn new skills, love to absorb information, love to understand new ideas. What I have not found in any of these pursuits is an activity that defines "who I am."
Maybe writing comes closest. Whatever professional direction I have taken, I have always been drawn toward the written word. But even with that, I have lacked the drive and willpower toward improvement that I think must be part of a true writer's personality.
What I find is that -- regardless of how much I enjoy an activity -- I will quite easily put it aside to pursue the next pursuit that strikes me as interesting.
Is there anything wrong with that? Or is it the mark of a curioof us mind? I like to think that the latter is true, but nevertheless as I look back, I think this lack of passion has kept me from reaching the upper echelons of any field.
I decided some time ago that that was okay, that I have had a diverse, interesting and rewarding life. But I can't say I don't wonder what I might have achieved if I had worked a little harder at any one of my many pursuits. When I finished college, I assumed that writing would be my life. I sought and won jobs with newspapers that allowed me to write everyday, and I suppose I improved my "reporting" capabilities over those 10 years, but at the end of it, I found that while I had made only a modest name for myself, I wanted to try something new -- it was time to start another learning curve.
Is there still time for excellence? Can passion be discovered late in life? Is there a chance that I may synthesize all of my experiences into something lasting, something that I might be remembered by? Is that even important?
Is it passion that's required, or is it discipline? Am I just too lazy to be a high achiever?
In some ways that seems absurd. I have always worked hard, prided myself on my output and worried that I am not doing "enough". Most of the time I finish individual projects that I start (a dollhouse for my daughter is a notable exception -- it sits unfinished in my garage 7 years later), but I get bored doing the same thing day after day.