the two sides are -
1. you only live once - so, if you have a passion and do not fulfill it while you can - you might suddenly be past the age with the passion long gone - and only regret for not indulging yourself while you could
2. you live for the future of your family - when one starts thinking of the fiscal future of dependents - austerity kicks in - and here lies the great danger - one might end up so austere that he/she becomes a menace!!

and interferes in the overall happiness of the family.
there are probably other sides to this -
regds