What is a change of circumstances that outweighs a previous overstay in a UK visa application? [closed]

I applied to the UK recently and I was refused on the grounds that I visited my friend for more than the days I applied for. I applied to spend three weeks and ended up spending 141 days and did not explain in my recent application. However, my visa did not expire. They further stated that my subsequent applications are likely to be refused unless my circumstances change. So I want to find out how my circumstances can change.