"Moms won't be around forever...you need to appreciate them while you can and not complain."
Apart from being a guilt-trippy platitude, this sentiment is not as beautiful or wholesome as people think it is. It is a faulty reasoning. Let me explain why I say this.
Yes, it is true, scary as it is: any person we love could be dead tomorrow. Heck, each of us could be dead tomorrow. Life is unpredictable and harsh sometimes. Experience irl, and stories we read in the hug folder, make that abundantly clear.
However, is that a reason to grin and bear every problematic behaviour of our loved ones today, to ignore every problem in our relationships
No. It is, on the contrary, a reason to voice and work out our differences with them, so that we can enjoy our relationship
, friendship, family ties to the fullest while we can. So that when they do pass away, we can look back on good memories, and not on a lifetime of unspoken resentment.
What is important though, in the context of "life can go out suddenly like a candle", is to always part on good terms, and to never forget to let people feel you love them, if you do.
(As far as all of this is possible, of course. For the sake of sanity, I'm talking in general here, and excluding toxic relationships
. For example, for myself I have no interest in trying to "enjoy family ties to the fullest" with my own toxic bio-mom, or letting her back into my life. That ship has sailed. I'm talking here only about normal situations with everyday annoyances that can be overcome.)