It's kind of funny how every year we get older and realize there were so many things that we didn't need to stress about so much in our past. My father once told me, "If it's not going to matter in 5 years, it doesn't really matter at all," and now I'm beginning to understand what he meant. Sometimes it can feel like older adults don't understand what younger adults are going through, but usually, they can. They literally went through it themselves and came out the other end okay it seems.
Of course, some things change, and we face different issues from our parents, but some pieces of advice, like many of the ones mentioned in this Reddit thread, will always be applicable.