How do you stay motivated?

I use to have quite strong motivation to go and put in work everyday. In the summer, I went for an extended holiday with my wife and we travelled for nearly a month.

Ever since then, I feel like I’ve had to force myself to go in to the gym. To be honest, I’ve been far from consistent, the days I didn’t train outnumber the days I did by a sizeable factor. I was also plagued by illness and injuries that put me out for several weeks.

I want to get back in and put in the hours, but I’m struggling to find motivation. How can I jumpstart myself?