Karolev was born in Varna on 31 July 1961. He completed his compulsory military service in Musachevo [bg] as a counterintelligence officer. He completed a master's degree in international economic relations at the Karl Marx Higher Institute of Economics in 1986, a master's in business administration at the University of Alberta in 1993, and a master's in real estate economics at the University of Reading in 2014.[2]
Karolev became famous in the mid-1990s due to his authorship of numerous articles on economics. In 2001, he actively participated in the NDSV election for Simeon Saxe-Coburg-Gotha. In 2003, he was elected to the Municipal Council of Sofia and was re-elected in 2007 and 2011. In 2011, he unsuccessfully ran for mayor of Sofia. That year, he resigned from the municipal council to focus on his professional career.
On 9 May 2021, Karolev disappeared following a splitboard accident on Todorka. He was rescued after a 12-hour operation and was found in critical condition. He was hospitalized in Razlog and placed in a medically induced coma. He was then transported to Pirogov Hospital in Sofia and placed in the intensive care unit.[3] In September 2021, he was transported to Acibadem City Clinic Tokuda Hospital. There, he died on 21 October 2021, at the age of 60.[4]