Super question! 
I was asked by someone once- 'Why are you taking photographs?? I mean, what's the point of spending all this money??'*
(*actually it was asked in a derisory tone- by someone who hasn't got an artistic bone in his body-but --interestingly enough--- is passionate about sport, which I for one ...can't stand)
I was caught on the hop at the time-and came up with an answer that could only be termed as a lame one.
So I thought about it- and applied the question to my underwater photography, scuba diving, and life in general..
If I was asked this question again-by the same individual...... this would be the answer....
I do it for the same reason that Leonardo DaVinci painted the Mona Lisa, why you follow your football team with a religious fervour (that I would find assinine)....why you take to the sports field in the p"*sing rain to get the seven shades of c*ap knocked out of you...
I do it because I can...I do it because I love to..... and I do it because it reminds me of how lucky I am to have the health, and the unconditional love and encouragement to do it.....and taking pictures makes me see the beauty of this world for what it is...and that I'm just a small transient part of it..
So Pam, celebrate your life thro' your muse...because it is short,....it is transient...and it is better to ......GO FOR IT WHEN YOU CAN...and sod the begrudgers!