"De vrolijke man kleedt zich eindelijk weer aan."
Translation:The cheerful man finally puts on clothes again.
EDIT: This response is not relevant to the original question. I'll keep the content here, however, as someone may find it helpful.
Eindelijk kleedt de vrolijke man zich weer aan.
By shifting eindelijk to the beginning of the clause it directs more emphasise towards "finally".
You know what.... I confused your question with a thought I had at the time regarding another concept xD I've been contributing much more to discussions over the past few days than I usually do, and I suppose I simply mixed up what I was thinking with the actual content of your question. Apologies for the mix up
I agree, your sentence is sound, and it should be an accepted translation of the original sentence.
"To dress" and "to dress up" are not the same in English. Just the ordinary act of putting on clothes is "to dress" (not usually any need to make it reflexive by adding "himself" - you can, but it doesn't add anything to the meaning - if he was dressing anyone else you would say so). "To dress up" is usually for a party or special occasion. It doesn't just mean putting on clothes, but smart or special clothes. In this example, the man just dressed, or got dressed, or put on clothes (any of those would be acceptable), but there's no evidence he "dressed up" - i.e. made a special effort.
"To dress up" could also mean in a costume - e.g. for a play. To "dress up" as Cinderella, for example.
Finally, "to dress up" can be used colloquially in English, to describe making something look better - sometimes, but not always, with the intent to deceive. So I could say: "I dressed up my presentation with lots of graphs" (might mean the presentation by itself was not very good, so I tried to disguise it).
Most of us in England are shy about correcting a foreigner's English unless they ask us to - it seems a bit rude - especially if we can still work out the meaning. That would probably be why nobody said anything. Or perhaps they thought you were very particular about clothing, and always liked to "dress up"? ;)
You can also "dress up" because it's cold, by the way - i.e. put on lots of clothes.
And you can "dress down" - i.e. deliberately more relaxed/casual. Some employers have: "Dress down Fridays" - either weekly, or once a month, when employees are not expected to wear formal business attire - they can wear their normal weekend clothes. I'm sure this concept is not unique to the UK - I expect NL has it, too.
Sometimes there's a charity element - i.e. you're expected to pay a small "fee" - which goes to charity - for the privilege of wearing jeans to the office.