My dad did something similar when he retired, before my mom retired. He concentrated on trips she had *no* interest in. For example his first trip involved loading up his pickup/shell with his kayak, a backpack, a mountain bike, and various gear and camping/hiking/kayaking/cycling up the coast of the US - then over to Vancouver Island, then ferrying among the Canadian and US islands up through Alaska, across BC, and back into the US at Glaciar Nat'l Park - then seeing all the Nat'l parks from Montana through Arizona, then home. 3 months. My mom had given up camping several years before due to bad ankles and a desire for indoor plumbing.
I traveled solo throughout my 30's till I met my husband. He also used to take international trips on his own... it was our love of travel that was one of our common interests when we first met.
You have more freedom traveling by yourself - see what you want to see, not have to wait while someone else gets ready, go back to the lodging for a nap when you are tired, not dependent on someone else's "must see" list for the day. But it's also lonelier. That said - I don't regret the many trips I took solo.