completely off topic - happy marriage/negative thoughts

I need your help ladies... I am what I consider very lucky. I have my soul mate, I believe that, always have. We have been married for 16 years but together for 25 years (living together almost 20). He is usually supportive, he's kind and caring, he's introspective about his shortcomings (even though initially angry that you brought them up) and tries hard to fix them or at least improve them because he loves me. He has come so far with such a tragic beginning. He's funny, he like to travel and take me new exciting places and he puts me first in many situations. So then why, do I go through periods of time where all of his negatives plague my mind? I mean, most of the time he can do no wrong and anything he does do wrong I can correct with a kiss and a hug and a playful nudge. It's that way most of the time, a beautiful relationship, so then why do I go through months of negative thoughts about him periodically? I hate it! Because bottom line I am never leaving this man, divorce is not something that is even in the equation. So then why have I thought about what it might be like to not be in this relationship. The thought sickens me. There is no one else, I only want him. I for one know, that the grass seems greener on the other side, but it usually has brown patches. Does anyone else go through periods when they have persistent negative thoughts about their DH? Please share your thoughts. I don't talk to people about it so it's all going on in this head of mine, which probably is not helping. I don't talk with other about my relationship because I have experienced women who want to trash their own relationship which only makes things worse in my own relationship. I would prefer input that steers me towards DH not away, that is why I want help. Any discussion towards that end or experiences that are similar and how you coped would be outstanding. Love you ladies.

~Michele