I've had a couple of past relationships that I felt I outgrew. Nothing wrong with the guys I was with (at least I didn't think so at the time) - I was in my 20s and still figuring out who I was and what I wanted in life. As I evolved, so did my goals, and therefore my priorities got shuffled around. While it didn't make me think any less of my partners, I did feel myself kind of "fall out of love" with them, but it was because I felt we were no longer compatible due to fundamental differences in shared values and goals.
From a more macro point of view on love, particularly the romantic variety, my feelings about love have evolved drastically - like it's an entirely different species now lol.
I used to believe and act as though love was:
Mutually self-sacrificial
Passion/excitement (read: drama/uncertainty)
Being dependent upon the other's love to be my own source of love, worthiness, value, desirability, approval/acceptance, and to fulfill all of my needs (and them dependent on me for the same)
The way they felt about me directly impacted how I felt about me
That rushing in and speeding through the relationship was a sign of passion and compatibility and meant-to-be-ness
"Giving my all" then feeling slighted, unloved, and unappreciated when they didn't do the same for me
Seeing how good a relationship partner could be based on what potential I saw in them and if I could just heal them or fix them or otherwise make them into the person I thought they should be then all of my sacrifices and suffering wouldn't be for naught
Not placing any (outward) demands or expectations on the other or the relationship, and shelving my own needs, wants, opinions, feelings, and boundaries to show how "low maintenance" I am and therefore a great catch
Ugh *shudders*. In short, I used love and relationships to prove my value and put the onus on my partner to make me happy. There's more, but it's actually difficult for me now to even remember my skewed definition of love in its entirety. Because it has changed so much and I was so irrational about it back then, what I used to consider love is no longer recognizable to me as such.
These days, I understand that love isn't a business transaction. It's not something we should have to do for or prove to another in the hopes that they'll love us back and validate our value, worth, and lovability. We shouldn't have to sacrifice ourselves or our mental/emotional/physical well-being - if that's what we or our partners expect, it's not love - it's servitude. Love doesn't demand that we "give our all" (aka give ourselves up) or take from ourselves until we have nothing left to give. A healthy relationship feeds both people involved - it doesn't starve us. Love doesn't require that we make ourselves smaller in order to be worthy of receiving it - it builds us up and makes us more of the best version of us and the other. Love allows us to be vulnerable and open about our needs, feelings, thoughts, opinions, hopes, dreams, fears - all in complete confidence and safety. If we can't be ourselves in relationships, what's the point? We can't throw ourselves under the love bus and feel all virtuous about it in the hopes that our partners will recognize our sacrifice as a badge of honor and give us our self-esteem and self-worth.
A truly loving, mutually fulfilling relationship between two healthy, mature adults is based on love, care, trust, and respect. There should be emotional availability, intimacy, consistency, progression, balance, presence, and commitment on both sides. Compatibility shouldn't be based on whether we like the same books, music, art, nor the level of passion and drama that's involved, but rather shared core values, goals, and priorities in a relationship.
So yeah. I think it's fair to say that my feelings about love grew opposable thumbs.