The first time I went to WDW with my now X-wife was in 1983. We went as a family, me, her and our two daughters. We divorced in 2001, after many trips there.
I started going alone after the divorce and can tell you that the only thing I thought about were the good memories. Divorce for any reason does not take away your past life, it only alters your present one. I remember the good times, the fun, the adventure and the shared experiences. Sometimes that makes me a little sad that we can no longer share those past memories while making new ones, but it is what it is.
Our divorce wasn't about cheating or abuse...it was about mental illness (not just my imagination...is was confirmed) that took over her life. She could no longer be married and left.
To be honest, even with the sad parts, I never really think about it as a woulda, shoulda, coulda type experience just a look back compared to present. I still enjoy my trips very much. It wasn't about us, it was about the place itself.
I do sometimes wish that I could find that person out there that I could not only love, but that could share my enjoyment of Disney and the parks. The longer I get in the tooth, however, the less likely that seem to be able to happen.