Who doesn't feel disappointed with life? Who doesn't fantasise about a different life? Or at least the details of our current life being somewhat different? We think, "If only..." (I'd taken that opportunity way back, or settled with a distant partner, or moved abroad or had children earlier etc, etc).
We could go 'way out there' and imagine (helpfully sometimes I think) that we were born into a completely different country, culture, family, skin colour, socio demographic etc. Clearly this can put our own lives into perspective. But we'll quickly come back to the place of, 'well that really quite clearly didn't happen and couldn't have happened as I'm here, in this country with this family etc'. But, we do tend to do it within the confines of what we know. I know I can imagine what life might be like if my husband hadn't had a brain tumour. Maybe you imagine what life might be like if you were to have someone else's wealth, or their health or their wife?!
Fact is you don't. Fact is, as my wise friend David says, "you don't get to get that". You get to get what you've got. So are you living fully in the life that you have. You are born in the era you're in, into the family you like (or don't) with the bank account, the body, mind and soul that you have. This is the life you get to have. SO...are you living it fully? Fully accepting of all that it contains and offers? This realisation and in time acceptance and then gratitude for your life (warts, blind husbands and all) is what will make your life meaningful.
It's your life, its unique, its filled with opportunity and meaning. Live it fully.