I do not feel as though people recognize when they've truly outgrown their partner and they're holding themselves back.. It is possible to have love for someone, but not be IN love with them anymore. What matters more is how you identify it and what exactly you do about it. But how do you know?
1. You want different things.
Relationships are about compromise and that's perfectly fine. But sometimes, what you want and need is so far off from your partner that it hurts you or seems impossible to address. Most of the time people ignore things like this, but it's absolutely possible to have wanted the same things at one point in your relationship, but for it to drastically change years later. If you have professional, educational, and financial goals that your spouse is not on board with, it will completely alter the dynamic of your relationship.
2. You are on an extremely different path.
This goes hand in hand with goals that you may have. Maybe you are seeking out growth and following your goals on your own, but your partner isn't a part of that process, isn't seeking growth, and prefers to stay home because they are content where they are in life. This sets you up for dissatisfaction because you want a true cheerleader, or someone that understands what you're going through. Some people even lose attraction to those who aren't always seeking growth.
3. Your partner has become extremely codependent.
Codependency is a trap many couples fall into. Every relationship is give AND take. It should always reciprocate and not one person should always be seeking to please the other. This can also be an extremely toxic situation to be in. When you fall forward and your partner falls behind, you will come to find that you have become the sole provider in the relationship. Maybe this doesn't mean "single income", but maybe it means you are the decision maker, the planner, the steady hand, the everything. Without you, the relationship just won't work. Or, you know if you left for a long period of time, something would fall apart dramatically or be messed up when you get back.
4. Being together is a challenge.
When you have outgrown your partner, you don't relate with them anymore. You learn that every goal you have will lose to your partner's interest and not match their wants. Compromise turns into sacrifice and that sacrifice turns into submission. You know that your ideas with be put down by them, so you don't really bother getting too excited by things anymore.
5. You feel "held back" by your partner.
In this circumstance, you feel as though you could accomplish more if you didn't have to deal with your spouse. You feel like your aspirations would actually work out if your spouse wasn't around, or talking down your dreams. This point is extremely simple... If your spouse wasn't around, you feel as though you would do better or accomplish more.
If you experience any of these things, I would tell you to immediately tell your spouse how you feel. Sometimes that means you both need to go to marriage counseling. But, you cannot go forward in your life feeling as though the person who is supposed to be the most important in your life, is the one who is pulling you back. If you have already done everything you can to fix this, it's time to move on. No matter how hard that may hurt. But sometimes you have to understand that the decisions you make have to contribute to a fulfilling life for you to live and you also set the example for those who look up to you.
Things may seem hard now, but they can get better. You just have to take some risks.