There are 4 things I learned when I was 25:
You do not have to be affectionate all the time to care for someone, in fact, caring can also mean a couple of texts or silence for a few days while you both live your lives happily and separately.
People do not care for you less when they’re busy with their own lives. It’s your reaction to them being their own person - and your ability to make yourself happy - that determines how they feel about you.
Not everyone reciprocates to your actions the same way. If you want someone to acknowledge, be interested in, or treat you a certain way for your efforts, all you have to do is let them know. They will try their personal best to accommodate that within their personal spectrum of feelings.
No one owes you 100% of them, not even after 30 years, because someone having a percentage of themselves is what keeps them sane at the end of the day and that’s okay.
These things are so important to learn.