What is the difference between a complaint and a statement? If theres anyone with a better set of social skills here to help a dude out lol

Ie when you're chilling watching TV and somebody asks you to go out, but you respond with no thanks, I'm tired. Would stating you're tired be considered a complaint?

Just had a similar action with an NT friend, who says I complain about being tired a lot. When I look back and I never bring it up unprompted, and they comment on my mood so i tell them whats up.. is there some social thing which simply stating you feel negative is seen as a complaint?

Edit: thanks so much for all the comments! I should have been more specific, the examples I gave were not my actual experiences. In fact if I were to be more specific, it's my roommate that made me think about this, and they never want to go out lol. But I can still gain some insight from the comments! But it was much more generalized. Actual interaction: we are going about our day and my roommate casually asks "hey how are ya" and I respond "a bit tired!" And they remark on how I complain about being tired a lot. Which surprised me because I was answering their question, and not getting long winded into it. Then it dawned on me maybe simply stating I feel negative is seen as a complaint by people. Iunno.