In many ways things get simpler and easier when you fully commit to your partner. Once you realize this is the person you want to do life with from now on, and you heed the call, something shifts internally, and you unlock new relationship superpowers. Here are a few you might notice:

You’re a yes to all of it. You still have likes and dislikes; they don’t just go away. There may still be annoyances or even significant relationship issues. And you certainly still strive to make the relationship better, maybe even more so. But it feels different. You’re a yes to all of it, the whole shebang.
You stop thinking about back doors. It’s easy to underestimate the mental load that gets freed up when you’re no longer doing that silent worth-it-or-not math, mulling over other options, or fighting an indecision you dare not reveal to your beloved.
Your partner is no longer the enemy. You’re on the same team. Believing your partner is the problem is an indulgence that becomes more difficult when they are also your chief co-conspirator in this game of life. The cognitive dissonance is too much. Besides, you know better.
Less competition, more collaboration. I use the word co-creation for a particular form of collaboration where you trust that your joint solutions are better than what either of you could come up with alone. You’re not negotiating compromises from polarized stances, you’re creating something new. Impasses just mean there’s a better solution that requires both of you working together to find. You are unique in the world, and your relationship has never existed before. You know your co-created life will continue to surpass your old conceptions of what a relationship “should” be.
Your love for your partner becomes steadier, because it’s no longer contingent. When you’re mad at them, you still love them. When you’re disappointed or hurt, you love them. It doesn’t come and go, it’s just there. There’s a baseline of love that doesn’t get drowned out by any other feelings that also arise.
You stop lone rangering in the relationship. You’re keenly aware of your own past tendencies that no longer feel right. Here’s where you would have made a unilateral decision that also impacts your partner. Here’s where you would have lied or hidden something from them to serve your personal needs. Here’s where you kept the peace or maintained the positive vibe, avoiding the uncomfortable conversations needed to make things better in the long run. Here’s where you tended to turn vicious and vindictive when you got angry. Here’s where you kept up a facade, not letting your closest intimate partner see you or know you fully. Whatever your lone wolf tendencies have been, it feels bad now to indulge them.
Your relationship becomes more adaptable, now that you’re not trying to crowbar a personal vision that predates the birth of the relationship. Co-creation is how you have a relationship that fits you both and lets you be yourselves.
You become more generous, because so many of your previous I’s are now We’s. There’s no longer any such thing as you being fulfilled or achieving your desires or being happy at the expense of your partner. That is a non-sequitur. You’re as highly motivated toward their fulfillment as you are your own.

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Does this list read like a litmus test? That wasn’t the intention, but we can go there. I’ll phrase it in terms of myself. As Ana would tell you, who I am with her now is worlds different than who I was able to be before I fully chose her.

If I were to get competitive with her, or try to “get mine” at her expense, or treat her with contempt, or hide something I know would matter to her, or keep some back-door options open, or lone ranger inside the relationship, or see her as the enemy…

I would be acting at cross-purposes to my desire for a thriving, fulfilling, joyful marriage. I would be abandoning life partnership for something else in the moment.

Ana is the person I’m going to be with for literally the rest of my life, and the single most important relationship I will ever have. Let that sink in. Why would I do that stuff? This relationship, this partnership, is infinitely more valuable to me than anything any of those behaviors can ever get me.

. . .

Before we go… there are also some notable things that don’t change with commitment.

You will continue to get to know each other. It’s been said that the human brain is the most complex object in the known Universe. Like I said, you’re both unique. You can spend a lifetime getting to know your partner.
Your relationship will continue to evolve. Let’s hope that you are a different person five years from now, ten years from now, and so is your partner. That’s not a bug, it’s what’s supposed to happen. Your relationship will evolve as you do. A synonym for longevity is change.
Togetherness will always be a daily choice. It may be a decision you never question in the slightest, one that hasn’t wavered since day one, but every day you’re together is still volitional. It’s a continual opt-in, not a one-and-done.